Whole  Number  293 


THE 

JOHNS  HOPKINS 
IJNFVERSITY  CIRCULAR 


741  $ 

CONTRIBUTIONS  TO 
GE-LOGY 

AND 

PLANT  PHYSIOLOGY 


BALTIMORE,  MARYLAND 
ISHED  BY  THE  UNIVEBSITY 
ISSUED  MONTHLY  FROM  OCTOBER  TO  JULY 
MARCH,  1917 


Entered,  October  21,  190C,  at  Baltimore,  Md.,  as  second  class  matter,  under 
Act  of  Cengu.     of  July  16,  1894 


BERKELEY 

LIBRARY 

UNIVERSITY  Of 

CALIFORNIA 

—    i  I. 

EARTH 


EXCHANGE 


CONTRIBUTIONS  TO 
GEOLOGY 

AND  * 

PLANT  PHYSIOLOGY 


t 


BALTIMORE 

THE  JOHNS  HOPKINS  PRESS 

1917 


--EART* 
SCIENCI 
UBRARt 

THE  JOHNS  HOPKINS  UNIVERSITY  CIRCULAR,  No.  293 


MARCH,   1917 


GECvLOGY  :  * 


CONTENTS 

PAGE 


••*  .'Gfeofrgicat  Surveys  Vith  Special  Reference  to  the  Work  of  the  Maryland  Geo- 
•.••  •    *  •  jlggjg^l.'Survty*.     W.   B.   CLARK 


3 

The  Use  of  Average  Analyses  in  Defining  Igneous  Rocks.     E.  B.  MATHEWS.   ...  12 

The  Delta  Character  of  the  Tuscaloosa  Formation.     E.  W.   BERRY  .........  18 

The  Role  of  Mineralizers  in  Ore  Segregations  in  Basic  Igneous  Rocks.  J.  T. 

SINGEWALD,    JR  ...................................................  24 

The  Environment  of  the  Tertiary  Marine  Faunas  of  the  Atlantic  Coastal  Plain. 

J.   A.   GARDNER  ...................................................  36 

The  Pelecypods  of  the  Bowden  Fauna.     W.  P.  WOODRING  ...................  44 

Origin  of  the  Natural  Brines  of  Oil  Fields.     F.  REEVES  ...................  57 

An  Upper  Cretaceous  Seacoast  in  Montana.     W.   T.   THOM,  JR  .............  68 

A  Remarkable  Upper  Cretaceous  Fauna  from   Tennessee.     B.  WADE  .........  73 

The  Occurrence  of  the  Tuscaloosa  Formation  as  Far  North  as  Kentucky. 

B.    WADE  ........................................................  102 

The  Habitat  of  Belemnitella  Americana  and  Mucronata,  G.  E.  DORSET  ......  107 

PLANT  PHYSIOLOGY: 

The  Department  of  Plant  Physiology.     B.   E.   LIVINGSTON  .................         133 

Publications  from  the   Laboratory  of   Plant  Physiology,    1909-1917  .........          154 

Atmometric  Units.     B.  E.  LIVINGSTON  ...................................         160 

The  Vapor  Tension  Deficit  as  an  Index  of  the  Moisture  Condition  of  the  Air. 

B.   E.   LIVINGSTON  ............................................  .....         170 

Incipient    Drying    and    Temporary    and    Permanent    Wilting    of    Plants,     as 

Related  to  External  and  Internal  Conditions.     B.  E.  LIVINGSTON  ........          176 

The   Effect  of   Deficient   Soil  Oxygen   on  the   Roots   of  Higher  Plants.     B.   E. 

LIVINGSTON  and  E.    E.   FREE  .......................................         182 

The  Experimental  Determination  of  a  Dynamic   Soil-Moisture   Minimum.     H. 

E.    PULLING  ...................................................  .  .         186 

Some  Unusual  Features  of   a  *Sub-  Artie  Soil.     H.    E.   PULLING  .............          188 

The  Geographical  Distribution  of  the  Citrus  Diseases,  Melanose  and  Stem-end 

Rot.     H.    S.   FAWCETT  .............................................         190 

Preliminary  Note  on  the  Relation  of  Temperature  to  the  Growth   of   Certain 

Parasitic   Fungi  in  Cultures.     H.    S.    FAWCETT  .......................          193 

Symptoms    of    Poisoning    by    Certain    Elements,    in    Pelargonium    and    Other 

Plants.     E.    E.    FREE  ..............................................          195 

The  Effect  of  Aeration  on  the  Growth  of  Buckwheat  in  Water-Cultures.     E.  E. 

FREE  .....  .......................................................         198 

The  Effects  of  Certain  Mineral  Poisons  on  Young  Wheat  Plants  in  Three-Salt 

Nutrient  Solutions.     E.  E.  FREE  and  S.  F.  TRELEASE  .................          199 

Leaf-Product  as  an  Index  of  Growth  in  Soy-Bean.     F.  M.   HILDEBRANDT  .....          202 

A  Method  for  Approximating  Sunshine  Intensity  from  Ocular  Observations  of 

Cloudiness.     F.   M.    HILDEBRANDT  ...................................         205 

Moisture  Equilibrium  in  Pots  of  Soil   Equipped   with  Auto-Irrigators.     F.    S. 

HOLMES  .........................................................         208 

Seasonal   Variations   in  the   Growth-Rates   of  Buckwheat   Plants   under   Green- 

house Conditions.     E.   S.    JOHNSTON  .................................          211 

On  the  Relation  of  Chlorine  to  Plant  Growth.     W.  E.  TOTTINGHAM  .........          217 

A   Study  of   Salt  Proportions   in   a   Nutrient   Solution   conaining   Chloride,   as 

Related  to  the  Growth  of  Young  Wheat  Plants.     'S.  F.  TRELEASE  .......          222 

The  Relation  of  the  Concentration  of  the  Nutrient  Solution  to  the  Growth  of 

Young  Wheat  Plants  in  Water-Cultures.     S.  F.  TRELEASE  .........  •  .....         225 

The  Effect  of  Renewal  of  Culture  Solutions  on   the   Growth  of  Young  Wheat 

Plants  in  Water-Cultures.     S.  F.  TRELEASE  and  E.  E.  FREE  ...........         227 


THE 

1      *>^  *  n  •' 

JOHNS  HOPKINS.,      V 
UNIVERSITY     CIRCULAR 

EDITED  BY  THOMAS  E.  BALL 

New  Series.  1917,  No.  3  MARCH,  1917  Whole  Number,  293 


CONTRIBUTIONS  TO 
GEOLOGY 


GEOLOGICAL  SURVEYS  WITH  SPECIAL  REFERENCE 

TO  THE  WORK  OF  THE  MARYLAND 

GEOLOGICAL  SURVEY  1 

By  WILLIAM  BULLOCK  CLARK 


A  discussion  of  the  organization  and  work  of  a  Geological 
Survey  would  not  be  complete  without  some  introductory 
words  regarding  the  origin  of  geological  surveys. 

Geological  knowledge  has  been  advanced  by  the  individual 
working  independently  either  in  a  private  capacity  or  under 
university  or  similar  auspices,,  or  by  a  group  of  individuals 
brought  together  in  an  official  organization,  controlled  gen- 
erally in  large  measure  by  the  lines  of  investigations  to  be 
followed.  Cooperation  is  of  course  possible  in  the  first  case 
but  not  absolutely  necessary,  while  team-play  is  an  essential 


1  Part  of  a  discussion  before  the  Scientific  Association  of  the  Johns 
Hopkins  University. 

201]  3 


854788 


4  Geological  Surveys  [202 

feature  of  the  Survey  no  matter  how  much  independence  may 
be  granted  in  individual  instances. 

Although;,  individual  effort  of  a  sporadic  sort  had  long 
not  until  the  appointment  of  Werner  in  1775 


ast  J^ofQSsor  at.  Freiberg  in  Saxony  that  geology  can  be  said 
\tcf  ^a^etSeeriv'recognized  as  an  independent  science  and 
admitted  as  such  into  academic  surroundings.  The  great 
influence  of  Werner  in  securing  recognition  for  geology, 
although  many  of  his  conceptions  were  erroneous,  has  led  to 
his  being  called  the  Father  of  Geology.  For  a  half-century 
after  his  time  much  work  was  done  by  private  initiative  both 
in  and  out  of  the  university  to  advance  the  science  of  geology, 
but  it  began  to  be  recognized  more  and  more  that  individual 
resources  were  inadequate  to  secure  the  vast  number  of  facts 
in  the  field  on  which  most  lines  of  geology  depend.  It  was 
then  that  public  aid  was  solicited  and  secured,  but  secured 
not  wholly  because  the  legislator  was  impressed  with  the  pos- 
sibility of  advancing  geology  for  its  own  sake  but  because  the 
geologist  was  able  to  impress  him  that  out  of  this  work  some- 
thing of  a  practical  nature  might  be  speedily  or  in  the  more 
distant  future  secured.  It  is  unfortunate,  perhaps,  that  the 
geologist,  if  he  is  to  secure  public  support  for  such  work,  must 
be  to  some  extent  what  is  called  a  lobbyist,  although  the  time 
and  energy  employed  are  not  wholly  lost  in  that  his  vision  is 
broadened  by  frequent  contact  with  men  of  affairs.  Not  all 
representatives  of  the  people,  to  be  sure,  consider  the  public 
interest  of  first  importance,  but  there  are  always  some,  often 
many,  who  do  ;  at  least  that  has  been  my  experience. 

It  is  to  America  that  we  have  to  look  for  the  first  recogni- 
tion of  the  part  the  public  may  play  in  the  support  of  geologi- 
cal work  through  legislative  appropriations,  and  it  was  North 
Carolina  that  established  the  first  official  Geological  Survey. 
This  was  in  1823,  when  the  General  Assembly  of  the  State 
authorized  the  Board  of  Agriculture  to  pay  the  expenses  of 
"  geological  excursions  "  for  a  period  of  years  and  appointed 
Professor  Denison  Olmsted,  of  the  State  University,  subse- 


203]  W.  B.  Clark  5 

quently  Professor  at  Yale,  to  direct  the  work.  South  Caro- 
lina followed  the  example  of  its  sister  State  in  1824  with 
Lardner  Vanuxem  in  charge;  then  Massachusetts  in  1830  with 
Edward  Hitchcock  as  State  Geologist,  the  first  important 
Survey,  as  the  Carolina  organizations  were  rather  insignificant 
affairs;  then  Tennessee  in  1831  with  Dr.  Gerard  Troost  as 
Geologist;  then  Maryland  in  1833  with  Jules  T.  Ducatel,  a 
graduate  of  the  Sorbonne,  as  State  Geologist,  and  J.  T.  Alex- 
ander as  State  Topographical  Engineer.  Alexander  has  the 
credit  of  attempting  the  production  of  the  first  topographical 
maps  in  the  country,  and  although  they  were  very  crude  they 
possess  much  of  historical  interest.  In  1835  the  Virginia 
Survey  was  inaugurated  with  W.  B.  Eogers  as  Director,  the 
New  Jersey  Survey  with  H.  D.  Eogers  in  charge,  and  the  Con- 
necticut Survey  with  J.  G.  Percival  and  Charles  U.  Sheppard 
as  Geologists.  The  following  year,  1836,  saw  the  inauguration 
of  the  important  Survey  of  New  York  with  such  men  as  W.  W. 
Mather,  Ebenezer  Emmons,  Lardner  Vanuxem,  Thomas  A. 
Conrad,  and  James  Hall  as  Geologists,  and  of  the  Pennsyl- 
vania Survey  which  secured  H.  D.  Eogers  from  New  Jersey, 
and  also  the  surveys  of  Georgia  with  John  E.  Cotting  as  State 
Geologist,  and  of  Maine  with  Charles  F.  Jackson  at  the  head. 
Following  these  come  in  succession  the  Surveys  of  Delaware, 
Ohio,  and  Michigan  in  1837,  Ehode  Island  in  1839,  New 
Hampshire  in  1840,  Vermont  in  1845,  Alabama  in  1847, 
Mississippi  in  1850,  Illinois  in  1851,  Wisconsin  and  Florida 
in  1853,  Iowa  in  1855,  Arkansas  in  1857,  Texas  in  1858,  and 
California  in  1860,  so  that  prior  to  the  Civil  War  only  a  few 
of  the  then  existing  States  were  without  official  Geological 
Surveys.  The  leading  men  of  their  time  in  American  geology 
were  in  charge  of  this  official  work,  organized  at  the  public 
expense.  Hitchcock,  Emmons,  the  Eogers  brothers,  Vanuxem, 
Conrad,  Hall,  and  the  others  I  have  named  comprised  the 
chief  workers  of  their  day. 

The  Federal  Government  up  to  this  time  had  done  little  to 
subsidize  geological  research.    Some  explorations  of  the  west- 


6  Geological  Surveys  [204 

ern  country  had  been  inaugurated  in  which  geology  consti- 
tuted a  part  of  the  prospective  plans.  Among  the  more  pro- 
ductive of  such  investigations  were  those  made  by  David  Dale 
Owen  under  the  United  States  Land  Office  and  Treasury 
Department  in  the  upper  Mississippi  valley  region  in  Iowa, 
Illinois,,  Wisconsin,  Minnesota,  and  Nebraska  in  various  years 
from  1839  to  1851  and  by  the  distinguished  geologists  and 
paleontologists  Newberry,  Marcou,  Blake,  Conrad,  Hall,  and 
others  in  connection  with  the  Pacific  Eailroad  Surveys  from 
1853-55  under  the  War  Department. 

Only  a  single  foreign  government  had  inaugurated  official 
geological  work  during  the  early  portion  of  this  period.  The 
Ordinance  Survey  of  Great  Britain  in  1830  made  a  small 
grant  to  H.  F.  De  la  Beche  for  the  survey  of  southwest  Eng- 
land, but  it  was  not  until  later  that  he  was  definitely  appointed 
to  make  a  Geological  Survey.  Spain  and  Austria  established 
Geological  Surveys  in  1847  and  1849,  respectively,  but  it  was 
not  until  the  next  decade  that  similar  organizations  were  suc- 
cessively established  in  Bavaria,  Portugal,  the  Netherlands, 
Norway,  Sweden,  and  Switzerland.  Some  years  passed  before 
the  other  foreign  governments  followed  suit. 

Following  our  Civil  War  the  American  Government,  recog- 
nizing the  necessity  of  acquiring  information  regarding  our 
great  western  country,  established  four  exploratory  geological 
organizations,  two  under  the  auspices  of  the  War  Department, 
the  U.  S.  Geological  Exploration  of  the  40th  Parallel  under 
Clarence  King,  and  the  U.  S.  Surveys  west  of  the  100th 
Meridian  under  G.  M.  Wheeler,  and  two  under  the  auspices  of 
the  Interior  Department,  the  U.  S.  Geological  Survey  of  the 
Territories  under  H.  V.  Hayden  and  the  U.  S.  Geographical 
and  Geological  Survey  of  the  Eocky  Mountain  Region  under 
J.  W.  Powell.  They  were  finally  combined  in  1879  with  the 
title  of  U.  S.  Geological  Survey,  under  Clarence  King  as  first 
Director,  and  this  organization  with  appropriations  exceeding 
$1,000,000  annually  is  now  conducting  work  in  every  section 
of  the  country  although  devoting  its  chief  energies  to  the 
West. 


205]  W.  B.  Clark  Y 

At  the  present  time  nearly  every  State  in  the  Union  is  also 
carrying  on  its  own  official  work,,  generally  with  some  form  of 
cooperation  with  the  Federal  organization. 

The  State  Geological  Survey  of  Maryland,  as  at  present 
organized,  began  its  operations  in  the  spring  of  1896  and  is 
thus  over  twenty  years  old.2  Like  many  other  similar  organi- 
zations the  Maryland  Survey  is  carried  on  in  conjunction 
with  the  geological  department  of  its  leading  University.  In 
States  where  State  universities  exist  they  are  often  the  head- 
quarters of  such  work. 

The  primary  object  of  a  geological  survey  is  to  determine 
and  describe  the  geological  formations  and  depict  the  results 
on  maps.  In  order  to  classify  these  formations  intelligently 
one  must  establish  criteria  for  their  discrimination  based  not 
only  on  their  original  lithological  and  paleontological  charac- 
teristics but  also  on  their  often  highly  changed  texture  and 
structure.  In  such  a  region  as  Maryland,  which  has  repre- 
sentatives of  many  types  of  rocks,  nearly  every  phase  of  geo- 
logical investigation  is  involved.  For  this  reason  it  affords  a 
magnificent  field  of  study  for  the  student  and  has  been  so 
employed  in  the  training  of  several  score  of  graduate  students 
at  this  University.  The  State  also  benefits  in  that  it  has  at 
its  command  many  trained  or  partially  trained  men  without 
the  expense  of  a  permanent  staff. 

The  differentiation  of  geological  formations  and  their  repre- 
sentation on  maps  has  passed  through  many  interesting  phases, 
and  a  few  words  in  this  place  regarding  the  history  of  geo- 
logical maps  may  not  be  inappropriate.  As  far  back  as  the 
end  of  the  17th  century  a  scheme  for  depicting  the  mineral 
products  of  a  country  upon  a  map  was  submitted  to  the  Eoyal 
Society  of  London  and  appears  in  the  Philosophical  Trans- 
actions under  the  quaint  title  of  "  An  ingenious  proposal  for  a 


2  The  Ducatel- Alexander  Survey  came  to  an  end  in  1842  and  tho 
only  official  State  geological  work  of  any  importance  carried  on  in 
Maryland  after  that  time  until  the  organization  of  the  present 
Survey  was  by  Philip  T.  Tyson  who  as  State  Agricultural  Chemist 
from  1858  to  1862,  prepared  the  first  geological  map  of  the  State. 


Geological  Surveys  [206 

new  sort  of  Maps  of  Countrys,  together  with  tables  of  sands 
and  clays,,  such  chiefly  as  are  found  in  the  north  parts  of  Eng- 
land, drawn  up  about  ten  years  since,  and  delivered  to  the 
Eoyal  Society,  March  12,  1683,  by  the  Learned  Martin  Lister, 
M.  D."  3  The  first  attempt  at  a  geological  map  was  appar- 
ently made  by  Christopher  Packe  in  1743  when  he  published 
with  an  accompanying  tract  "A  new  philosophic  chorographi- 
cal  Chart "  of  East  Kent,  England,  covering  an  area  of  about 
thirty- two  square  miles.  The  object  of  the  map  was  chiefly 
to  delineate  the  topography  and  agricultural  soils,  while  the 
geological  indications  are  confined  to  notices  of  the  position 
of  sea  beaches,  gravel  pits,  chalk  pits,  etc. 

Much  more  complete  maps  of  this  character  covering  chiefly 
northern  France  on  which  the  mineral  substances  were 
grouped  in  bands  were  communicated  in  connection  with  a 
memoir  by  Guettard  in  1746  to  the  Academy  of  Sciences  of 
Paris.4  Following  these  came  maps  of  the  same  character  by 
Fiichsel5  in  1762,  by  Guettard  and  Lavoisier  about  1770, 
when  twenty-nine  uncolored  geological  sheets  of  the  map  of 
France  were  issued;  by  Guettard  and  Monnet  in  1780,  when  a 
folio  of  thirty-two  sheets  accompanying  a  mineralogical  de- 
scription of  France  was  published,  and  by  Desmarest  in  1771, 
when  an  uncolored  Geological  Map  of  the  Auvergne  was 
prepared.6 

The  first  colored  geological  map  is  the  work  of  Glaser,  who 
in  1775  depicted  in  colors  a  small  district  in  Saxony  about 
twenty  miles  long  by  fifteen  miles  broad,  three  tints  being 
used :  red  for  granite  rocks  with  a  blue  dotted  line  to  distin- 
guish apparently  one  kind  of  crystalline  rock  from  another, 
yellow  for  sand,  and  gray  for  limestone.  Factories,  limekilns, 
and  coal,  iron,  copper,  silver,  and  gold  deposits  were  indicated 
by  signs. 


3  Phil.  Trans.,  vol.  xiv,  p.  739. 

*Mem.  Acad.  Roy.  Frcmce,  vol.  for  1746,  pp.  343-392. 
5 "  Historia  Terrae  et  Maris,  etc."     Acta  Acad.  elect.  Moguntinae 
1762,  pp.  44-209. 
6  Mem.  Acad.  Roy.  France,  vol.  for  1771,  pp.  705-775. 


207]  W.  B.  Clark  9 

In  1778  Charpentier7  published  a  book  on  the  mineralogy 
of  Saxony  accompanied  by  a  so-called  petrographic  map  on 
which  red  is  used  for  granite,  purple  for  gneiss,  pink  for 
schists,  blue  for  limestones,  gray  for  gypsum,  yellow  for  sand- 
stone, drab  for  river  sand,  and  green  for  clay  and  loam. 

Palassou  in  1781 8  published  an  essay  on  the  Mineralogy  of 
the  Pyrenees  in  which  the  routes  in  the  south  of  France  are 
colored  according  to  the  rocks  they  cross :  green  for  granite, 
yellow  for  schists,  and  red  for  limestone,  while  sands,  sand- 
stones, and  clays  are  indicated  by  signs,  as  are  also  extinct 
volcanoes. 

Much  the  most  important  of  these  early  colored  geological 
maps  were  those  of  William  Smith,  who  prepared  fifteen 
county  geological  maps  of  England  between  1794  and  1821. 
These  and  his  general  geological  map  of  England  published 
in  1815  mark  the  beginning  of  modern  geological  cartography. 
Many  refinements  have  been  introduced  in  subsequent  years 
and  an  attempt  more  or  less  successful  has  been  made  to 
secure  cooperation  on  the  part  of  geologists  the  world  over  in 
the  use  of  the  same  colors  for  rocks  of  the  same  age  and  char- 
acter. At  first  all  maps  were  colored  by  hand,  but  in  recent 
years  lithographic  processes  have  been  introduced,  although 
the  Geological  Survey  of  Great  Britain  continued  to  color  its 
geological  maps  by  hand  until  a  few  years  ago.  The  Mary- 
land Survey  has  made  only  colored  lithographic  geological 
maps. 

In  addition  to  the  strictly  geological  work  carried  on  by  the 
instructors  and  students  of  the  Geological  Department  to 
which  I  shall  again  presently  refer,  the  Survey  has  secured 
the  cooperation  of  the  staffs  of  several  Federal  and  State 
Bureaus  (1)  in  the  making  of  the  base  topographic  maps, 
necessary  not  only  for  the  geological  but  other  kinds  of  sur- 
veys; (2)  in  the  classification  and  platting  of  the  agricultural 
soils  which  are  the  disintegrated  surface  portions  of  the  geo- 


Mineralogische  Geog.  d.  Chursachsische  Lande,  1778. 
Essai  sur  la  Mineralogie  des  Monts  Pyrenees,  Paris,  1781. 


10  Geological  Surveys  [208 

logical  formations  combined  with  vegetable  debris  or  humus ; 
(3)  in  determining  the  magnetic  elements  of  variation, 
declination,  and  force  so  much  affected  by  the  underlying 
rocks,  and  (4)  in  the  study  of  the  surface  and  underground 
waters  so  largely  dependent  on  the  geological  structure.  In 
addition  to  these  lines  of  work  the  Survey  was  directly  con- 
cerned in  the  past  in  organizing  the  modern  methods  of  state 
highway  construction  which  were  introduced  in  1898,  and  for 
ten  years  thereafter  it  was  the  only  state  agency  intrusted  with 
this  important  service  and  until  the  transfer  of  its  Highway 
Division  in  1910  to  the  newly-organized  State  Roads  Com- 
mission, on  which  it  also  had,  by  law,  influential  representa- 
tion until  1914.  During  this  time  the  Survey  built  150  miles 
of  public  highways  at  an  expenditure  of  nearly  $1,500,000,  but 
more  than  that,  developed  standards  of  work  and  a  trained 
engineering  force  that  today  largely  control  this  important 
public  enterprise. 

The  Survey  has  also  participated  in  the  re-surveys  of  many 
of  the  state  boundaries,  including  the  re-survey  of  the  Mason 
and  Dixon  Line,  and  also  of  several  county  boundaries.  It 
has  made  extensive  geological  and  mineral  exhibits  at  the  Buf- 
falo, Charleston,  St.  Louis,  Jamestown,  and  San  Francisco 
Expositions,  the  more  important  materials  then  secured  being 
today  maintained  as  a  permanent  exhibit  in  the  Old  Hall  of 
Delegates  in  the  State  House  at  Annapolis. 

Returning  now  to  the  strictly  geological  work  of  the  Survey, 
I  wish  to  call  attention  to  the  fact  that  some  of  our  official 
organizations,  carried  away  by  the  clamor  for  immediately 
practical  results,  are  devoting  their  time  much  more  than  in 
the  past  to  present  commercial  needs,  ignoring  the  fact  that 
their  greatest  service  to  the  public  is  in  studying  the  funda- 
mental scientific  problems  furnished  by  the  rocks  even  when 
they  appear  to  afford  no  application  to  the  industries  of  today. 
I  feel  that  a  Survey  that  is  continually  thinking  of  the  practi- 
cal results  it  can  secure  should  not  have  the  name  of  geologi- 
cal, for  I  dislike  to  feel  that  geology  has  no  higher  public 


209]  W.  B.  Clark  11 

value  than  to  provide  means  for  the  shrewd  business  man  who 
may  employ  its  results  to  acquire  a  few  more  dollars.  It  is  my 
belief  that  if  the  work  of  a  Geological  Survey  is  properly  done, 
with  one  regard  to  the  solving  of  the  scientific  problems  as 
they  arise,  it  will  indirectly  do  the  commercial  interests  of  the 
community  a  greater  service  in  the  end  than  if  the  practical 
aspects  of  the  work  are  given  first  place.  It  would  not  be  diffi- 
cult to  demonstrate  this  in  the  case  of  our  Geological  Surveys 
if  I  had  the  time. 

Maryland  possesses  three  provinces :  first  the  Coastal  Plain 
which  consists  of  the  low-lying  country  extending  from  the 
ocean  front  to  a  line  drawn  through  Elkton,  Havre  de  Grace, 
Baltimore,  Laurel,  and  Washington,  which  consists  of  nearly 
unaltered  sediments  of  relatively  simple  structure,  the  basal 
members  of  which  date  well  back  in  geological  time,  in  fact, 
before  the  Eocky  Mountains  or  the  Alps  were  formed.  They 
afford  a  series  of  problems  of  great  interest  but  quite  different 
from  those  of  the  other  areas. 

Lying  to  the  west  of  the  landward  border  of  the  Coastal 
Plain  and  extending  to  the  base  of  the  Catoctin  Mountain  is 
a  second  area  known  as  the  Piedmont  Plateau  consisting  of 
highly  metamorphosed  crystalline  rocks  cut  by  intrusive  and 
extrusive  eruptive  rocks,  the  whole  subjected  to  extensive 
deformation  with  intricate  folds  and  faults.  The  rocks  are 
very  old  and  probably  comprise  the  southern  extension  of  the 
great  Canadian  shield,  the  oldest  portion  of  the  North  Ameri- 
can continent.  Here  are  problems  of  great  interest  to  be 
solved. 

Beyond  and  extending  to  the  western  limits  of  the  State  is 
a  third  area  known  as  the  Appalachian  Eegion  that  contains  a 
great  thickness  of  deposits  lying  in  large  part  intermediate  in 
position  both  as  regards  age  and  structure  between  those  of  the 
Coastal  Plain  and  the  Piedmont  Plateau.  Along  their  east- 
ern margin  they  are  metamorphosed,  folded,  and  faulted  with 
a  large  admixture  of  eruptive  rocks  that  become  progressively 
less  complicated  westward.  In  this  district  still  other  prob- 
lems are  presented. 


12  Analyses  of  Igneous  Rocks  [210 

I  might  go  on  and  enumerate  in  much  greater  detail  the 
innumerable  questions  which  such  an  area  as  Maryland  pre- 
sents to  the  geologist.  We  have  been  engaged,  as  I  stated 
earlier,  for  over  twenty  years  in  trying  to  reach  a  solution  of 
some  of  these  problems,  but  our  successors  will,  I  am  sure, 
find  enough  to  keep  them  fully  occupied  for  another  genera- 
tion if  it  is  not  vouchsafed  for  us  to  keep  actively  employed 
in  studying  them  during  that  time.  The  question  may  be 
asked,  is  often  asked  by  the  custodians  of  the  public  funds, 
will  this  work  never  end  ?  But  I  must  answer  no,  not  as  long 
as  there  is  a  science  of  geology  worthy  of  the  name. 


THE  USE  OF  AVERAGE  ANALYSES  IN  DEFINING 
IGNEOUS  ROCKS 


By  EDWARD  B.  MATHEWS 


There  is  usually  associated  with  the  consideration  of  rock 
names  and  their  meanings  some  attempt  to  represent  the 
characteristic  chemical  composition  connoted  by  the  name. 
The  methods  employed  usually /consist  of  the  presentation 
either  of  a  series  of  analyses  of  individual  rocks  with  little  or 
no  discussion  of  their  meaning  or  of  an  arithmetical  mean  of 
a  varying  number  of  such  analyses  in  the  form  of  an  "  aver- 
age "  analysis  also  without  discussion  of  the  departures  from 
such  averages  which  may  be  shown  by  the  analyses  on  which 
this  "  average  "  is  based.  Neither  of  these  methods  is  very 
satisfactory  for  teaching  or  textbooks. 

The  presentation  in  columnar  form  of  a  series  of  analyses 
each  of  which  includes  from  eight  to  fifteen  determinations 
bewilders  the  student  who  seldom  stops  to  consider  just  what 
the  variations  amount  to  either  absolutely  or  relatively,  or 
what  relations  the  variants  bear  to  the  general  type.  This 
method  of  enumerating  the  actual  composition  of  individual 
rocks  may  be  eminently  proper  in  a  Handbook  but  fails  of  its 
purpose  in  a  textbook. 


211]  E.  B.  Mathews  13 

The  presentation  of  a  single  "  average  "  analysis  possesses 
all  the  charm  of  simplicity  and  ease  of  comprehension  but 
fails  to  convey  a  proper  conception  of  the  complex  variability 
underlying  it.  The  student,  with  retentive  memory,  may  hold 
the  values  assigned  to  the  type  but  may  gain  thereby  little 
knowledge  of  the  real  content  of  the  term.  If  the  rock  se- 
lected is  in  itself  sharply  defined.,  or  if  the  examples  collected 
are  sufficiently  numerous  the  "  average "  analysis  may  be 
satisfactory.  If,  on  the  other  hand,  the  individual  rocks  in- 
cluded under  a  given  name  are  aggregates  of  minerals  of  vary- 
ing composition  in  various  proportions  such  as  might  occur  in 
a  complex  of  numerous  related  and  unrelated  continuous  gra- 
dations without  any  semblance  of  "clustering,"  then  the 
"  average  "  analysis  gives  nothing  more  than  the  arithmetical 
mean  of  the  quantities  which  have  been  included.  As  Cross  x 
remarked  in  his  criticism  of  the  classification  proposed  by 
Loewinson-Lessing,  "  the  grist  of  this  mill  depends  entirely 
upon  what  is  put  into  the  hopper." 

While  even  a  momentary  consideration  shows  that  what  has 
been  said  regarding  individual  concepts  applies  even  more 
strongly  to  group  concepts,  the  writer  has  considered  it  worth 
while  to  test  quantitatively  the  variabilities  actually  involved 
in  "  average  "  analyses.  The  test  is  limited  to  anorthosites 
and  non-feldspathic  pyroxenites  and  peridotites  and  the 
methods  employed  are  both  graphic  and  arithmetic. 

EXAMPLES 

Anorthosite  is  composed  of  approximately  a  single  mineral 
or  at  least  of  representatives  of  a  single  isomorphous  series. 
The  natural  presumptions  are  that  their  analyses  would  repre- 
sent a  continuous  series  and  their  -average  an  intermediate 
member.  A  graph  of  the  analyses  found  in  the  literature 
shows  no  such  evenly  distributed  series,  at  least  so  far  as  lime 
and  soda  are  concerned,  but  three  distinct  types;  one  with 


1J.  Geol.,  vol.  X,  1902,  p.  481. 


14  Analyses  'of  Igneous  Rocks  [212 

approximately  16%  CaO,  the  most  abundant  with  approxi- 
mately 10%  and  a  third  with  about  3%%.  While  the  usual 
"  average  "  analysis  of  anorthosite  would  represent  in  a  gen- 
eral way  the  more  abundant  variety  the  breadth  of  range,  the 
discontinuity  of  the  series  and  the  existence  of  grouping  is 
obscured. 

Dunite  (Fig.  1)  is  another  rock  consisting  largely  of  a  single 
mineral.  Here  the  analyses  shows  little  variation  except  in 
the  ferrous  iron  which  shows  an  absolute  range  of  10%  and  a 
relative  range  of  156%  of  its  mean  amount.  Magnesia  shows 
an  absolute  range  of  7%  or  about  15%  of  the  average  content. 
The  isomorphism  of  the  olivine  group  would  suggest  more 
uniform  departures  of  the  iron  and  magnesia  from  their  aver- 
age values. 

Horriblendite  (Fig.  2)  is  a  third  representative  of  rocks 
composed  essentially  of  a  single  mineral  or  mineral  group. 
Here  the  possibility  of  alumina  in  the  molecule  suggests 
wider  departures  from  the  average  but  the  analyses  show  an 
absolute  range  in  alumina  of  scarcely  9%,  although  nearly 
80%  of  the  average  content.  Ferric  iron  shows  about  the 
same  absolute  range  but  a  much  greater  relative  range  because 
of  its  lower  average  content.  Ferrous  iron,  on  the  other  hand, 
with  an  average  content  similar  to  that  of  alumina,  shows  a 
relative  range  of  175%,  while  magnesia  and  lime  show  total 
ranges  of  less  than  100%  of  the  average  content. 

From  the  foregoing  it  seems  reasonable  to  infer  that  con- 
clusions based  upon  "  expansions  "  of  averages  in  accordance 
with  the  known  isomorphism  of  constituent  minerals  are  un- 
certain even  in  monomineralic  rocks. 

Turning  to  rocks  consisting  essentially  of  olivine  with  one 
or  more  pyroxenes  or  hornblende  two  rocks  were  selected. 

Uarzburgite  or  Saxonite  (Fig.  4)  composed  of  olivine  and 
an  orthorhombic  pyroxene  shows  several  variant  types  which 
are  entirely  obscured  in  an  average  analysis.  The  rocks  which 
have  been  named  harzburgite  compared  with  those  called 
Saxonite  generally  show  lower  alumina  and  lime  with  higher 


213] 


E.  B.  Mathews 


J5 


FIG.  1  TO  8. 

Graphs  showing  composition  of  igneous   rocks   used   in    obtaining 
average  analyses. 


16  Analyses  of  Igneous  Rocks  [214 

magnesia  and  similar  silica,  ferric  and  ferrous  iron.  These 
variants  may  be  due  to  chance  and  their  distinctness  to 
paucity  of  example,  but  such  differences  as  may  exist  are 
obliterated  by  the  use  of  an  "  average  "  or  even  "  typical " 
analysis. 

Lherzolite  (Fig.  3)  consisting  of  olivine,  bronzite  and 
diallage  shows  on  the  whole  a  wide  but  uniform  distribution 
in  the  content  of  the  various  constituents  in  the  analyses  at 
hand.  The  graph  shows  the  abnormality  of  the  Iherzolite 
from  the  Protrero,  San  Francisco  with  its  low  magnesia  and 
high  lime  which  raises  a  question  as  to  the  applicability  of 
its  name. 

All  of  the  examples  thus  far  considered  have  been  named  by 
workers  of  different  experience  and  training  and  the  sugges- 
tion comes  that  the  variations  in  composition  are  due  in  part 
at  least  to  incomplete  comprehension  of  the  content  of  the 
terms  used  or  to  personal  variations  in  usage.  To  illustrate 
range  acceptable  without  these  factors  two  sets  of  examples  of 
unique  types  studied  by  single  workers  were  selected. 

Koswite.  Composed  essentially  of  olivine  and  magnetite 
with  diopside,  and  some  hornblende,  and  chromite  includes  a 
series  of  magnetite  pyroxenites  described  from  the  Urals. 
They  are  characterized  chemically  by  high  ferric  and  ferrous 
irons.  While  the  analyses  are  incomplete  through  lack  of 
alkalies  their  summation  is  in  every  instance  over  100,  show- 
ing that  this  lack  does  not  vitiate  them  for  the  present 
purpose. 

The  departures  from  the  mean  of  values  for  the  individual 
constituents  is  here  usually  only  two  or  three  per  cent,  or  less 
than  50%  of  the  value  of  the  dominant  constituents. 

Ariegites  as  defined  by  Lacroix  are  a  group  of  pyroxenites 
characterized  by  the  constant  association  of  one  or  more 
pyroxenes  and  a  spinel  with  varieties  due  to  the  presence  of 
garnet  and  hornblende. 

In  this  series  the  absolute  range  is  4%  to  8%  and  the  de- 
partures in  the  case  of  the  principal  constituents  is  not  over 
10%  of  the  mean  values. 


215]  V.  B.  Mathews  17 

From  the  foregoing  it  would  appear  that  mature  workers 
even  in  establishing  their  types  believe  it  allowable  to  include 
rocks  whose  dominant  constituents  show  departures  ranging 
from  10%  to  30%  from  their  mean  values. 

The  use  of  average  analyses  in  the  description  of  rock 
groups  may  or  may  not  prove  more  serviceable.  "While  there 
are  more  possible  variations  in  the  kinds  and  proportions  of 
minerals  the  graphs  may  show  no  wider  variations  than  those 
noted  in  discussing  individual  types.  Thus  the  diagram 
(Fig.  7)  showing  pyroxenites,  exclusive  of  the  websterites 
(Fig.  8)  although  representing  several  kinds  and  many  ex- 
amples of  pyroxenites,  is  not  much  more  confusing  or  variable 
than  that  for  the  websterites  by  themselves.  The  peak  for 
lime  is  more  marked  but  the  predominance  of  the  magnesia 
and  lime  with  the  subordination  of  the  irons  and  alumina  are 
nearly  as  clear.  The  more  general  diagram  carries  aberrant 
types  like  the  pyroxenite  from  Rosetown,  N.  Y.  (high  alumnia 
and  low  magnesia)  and  the  magnetite  pyroxenite  from  Cen- 
tral City,  Colo,  (high  in  irons) .  The  former  is  a  poor  analy- 
sis while  the  latter  is  recognized  as  aberrant  and  their  inclu- 
sion in  any  general  average  analysis  is  doubtful. 

Similar  graphs  of  gabbro,  dacite  and  camptonite  show 
fairly  well  defined  figures  which  indicate  that  the  impressions 
gained  from  average  analyses  while  incomplete  may  not  be 
incorrect  in  the  major  essentials.  Average  analyses  cannot  be 
expected  to  bring  out  minor  "  clusterings  "  or  many  of  the 
relationships  in  constituents  which  are  disclosed  by  the  simple 
serial  diagrams  here  employed. 

The  same  is  true  of  several  of  the  systems  of  projection  now 
employed  in  petrography.  These,  moreover,  often  require  ex- 
perience and  maturity  beyond  that  of  the  average  student  of 
systematic  petrography  for  their  complete  appreciation. 


18  Tuscaloosa  Formation  [216 


THE   DELTA   CHARACTER   OF   THE   TUSCALOOSA 
FORMATION 

BY  EDWARD  W.  BERRY 


During  the  enormous  interval  of  time  represented  by  ma- 
rine sediments  in  other  parts  of  the  world  of  late  Carboni- 
ferous, Permian,  Triassic,  Jurassic  and  Lower  Cretaceous 
ages  the  southern  Appalachian  region  was  above  sea  level. 
Physiographically  the  southern  half  of  this  region  is  segre- 
gated at  the  present  time  into  the  Piedmont  Plateau,  the 
Appalachian  Mountains  (which  die  out  in  northwestern 
Georgia),  the  Appalachian  Valley,  the  Cumberland  Plateau, 
and  the  Interior  Lowlands.  Its  area  south  of  the  Ohio  Eiver 
is  over  160,000  square  miles,  and  the  actual  area  of  this  land 
mass  during  the  interval  from  the  Carboniferous  to  the  Upper 
Cretaceous  must  have  been  very  much  greater  than  this,  since 
nowhere  along  the  margins  of  this  massif  have  marine  sedi- 
ments of  these  ages  been  deposited  near  enough  to  its  present 
limits  to  be  reached  by  deep  borings  near  the  margin  of  the 
present  Coastal  plain. 

The  region  of  the  southern  Appalachians  is  one  that  has 
long  interested  physiographers.  Hayes  and  Campbell,  the 
chief  contributors,1  have  recognized  three  base  levels  or 
peneplains  which  they  term  in  the  order  of  their  ages  the 
Cumberland,  the  Highland  Rim  and  the  Coosa.  They  con- 
sider that  the  original  Tennesee  River,  which  they  term  the 
Appalachian  Eiver,  flowed  southwestward  by  way  of  the  valley 
of  the  Coosa  Eiver  throughout  the  Upper  Cretaceous  and  the 
major  portion  of  the  Tertiary  until  it  was  diverted  by  stream 
capture  due  to  the  working  back  across  Walden  Eidge  of  a 
stream  in  the  Sequatchie  valley  to  the  west  of  that  ridge. 


1  Hayes,  C.  W.  and  Campbell,  M.  R.,  "The  Geomorphology  of  the 
Southern  Appalachians,"  Natl.  Geographic  Magazine,  vol.  6,  pp.  63- 
126,  1894;  Hayes,  C.  W.,  "The  Physiography  of  the  Chattanooga 
District,"  U.  S.  Geol.  Survey,  19th  Ann.  Rept.,  Ft.  2,  pp.  1-58.  1899. 


217] 


E.  W.  Berry 


19 


This  spectacular  river  capture  has  been  disputed  by  Johnson 2 
who,  it  seems  to  me,  conclusively  demonstrates  that  the  pre- 
sent course  of  the  Tennessee  River  across  Walden  Ridge  in  a 
winding  gorge  is  imposed  from  meanders  inherited  from  the 


FIG.  l. 

Map   showing   physiographic   regions   and   areas   of    outcrop    of 
Tuscaloosa,  Eutaw,   and   Selma  formations. 

period  of  earliest  complete  baselevelling  in  this  area,  namely 
from  the  Cumberland  peneplain. 

The  character  of  the  Upper  Cretaceous  sediments  of  the 
eastern  Gulf  area  throw  considerable  light  on  the  physical 


2  Johnson,  D.  W.,  "  The  Tertiary  History  of  the  Tennessee  River..' 
Jour.  GeoL,  vol.  13,  pp.  194-231,  1905. 


20  Tuscaloosa  Formation  [218 

history  which  has  interested  me  chiefly  in  connection  with  the 
interpretation,  in  terms  of  geologic  history,  of  the  extensive 
fossil  floras  that  have  been  found  in  the  earliest  Upper  Creta- 
ceous or  Tuscaloosa  formation  of  this  region. 

The  Tuscaloosa  formation  in  the  area  around  Tuscaloosa, 
Alabama,  and  for  some  distance  to  the  northwest  consists  of 
about  1,000  feet  of  predominantly  sandy  materials  which 
give  the  country  its  present  topography.  These  sands  are 
usually  light  in  color,  cross-bedded  and  micaceous — occasion- 
ally there  are  traces  of  glauconitic  layers.  There  are  heavy 
beds  of  gravel  made  up  of  well  rounded  quartz  and  sub- 
angular  chert  pebbles  in  about  equal  proportions  in  places, 
especially  toward  the  landward  margin  of  the  deposits  and 
northward  along  the  strike.  In  disconnected  and  interbedded 
lenses  there  is  a  considerable  amount  of  argillaceous  material 
— at  times  massive  or  heavy  bedded,  but  generally  laminated. 
Thin  seams  of  lignite  are  present  at  various  levels  but  these 
are  generally  only  a  few  inches  or  less  in  thickness.  The  clays 
are  often  oxidized  and  mottled  in  color  but  they  are  as  fre- 
quently very  carbonaceous  and  dark  in  color.  In  some  sec- 
tions, as  in  the  Big  Gully  section  southwest  of  the  town  of 
Tuscaloosa,  there  are  layers  filled  with  prostrate  logs  of  trees 
of  large  size.  Pyrite  and  ferruginous  oxide,  forming  locally 
indurated  sandstones  and  gravels  are  generally  distributed, 
and  finely  disseminated  gypsum  crystals  are  very  common. 

No  fossils  other  than  the  remains  of  land  plants  have  been 
found  in  the  Tuscaloosa  deposits.  Usually  the  plant  remains 
are  much  macerated  and  broken  by  water  transportation  and 
deposited  in  films  of  broken  fragments  in  the  laminated  beds. 
Drift  logs  are  common  and  these  occasionally  brought  down 
cobbles  imbedded  in  their  roots  (statement  based  on  speci- 
mens collected  in  lignitized  tree  roots).  There  appear  to 
have  been  areas  of  quiet  waters  at  certain  localities  where  the 
leaf  remains  in  the  clays  are  abundant  and  in  a  state  of 
preservation  indicating  that  they  grew  in  the  immediate 
vicinity. 

The  outcrop  of  the  Tuscaloosa  formation,  as  shown  in  the 


219]  E.  W.  Berry  21 

accompanying  sketch  map,  is  roughly  lunate  in  outline  with 
the  southeastern  horn  terminating  near  Montgomery,  Ala- 
bama, and  the  other  extending  as  an  attenuated  band  across 
western  Tennessee.  As  will  be  seen,  the  greatest  width  of 
outcrop  coincides  with  the  maximum  thickness  of  sediments 
in  a  belt  about  125  miles  in  length  which  is  at  right  angles 
to  the  axis  of  the  Appalachian  land  mass.  To  the  northward 
the  deposits  become  thinner,  are  prevailingly  gravels  and  are 
shown  by  the  fossil  plants  to  be  somewhat  younger  than  the 
main  body  of  the  deposits. 

In  the  interpretation  of  the  Tuscaloosa  deposits  with  their 
gravels  and  compound  oblique  cross-bedded  sands,  their  occa- 
sional traces  of  glauconite  and  their  abundance  of  driftwood, 
one  cannot  fail  to  be  impressed  with  their  delta-like  character. 
We  are  now  fairly  familiar  with  the  main  features  of  delta 
deposits  in  different  parts  of  the  world  3  and  Grabau  4  and 
Barrell5  have  recently  contributed  considerable  toward  the 
interpretation  of  Paleozoic  delta  deposits.  Eeturning  for  a 
moment  to  the  physiographic  history  of  the  Tuscaloosa  region 
we  find  that  there  are  no  sediments  later  than  Pottsville  age 
until  the  deposition  of  the  Tuscaloosa  in  the  earlier  Upper 
Cretaceous.  This  long  interval  resulted  in  the  nearly  com- 
plete baselevel  known  as  the  Cumberland  peneplain.  There 
must  have  been  some  regional  uplift  or  warping  at  the  begin- 
ning of  Tuscaloosa  time  to  account  for  the  sudden  augmenta- 
tion in  river  action  and  the  inauguration  of  the  large  delta 
or  series  of  deltas  along  the  southwestern  margin  of  the  land 
mass.  There  is  no  evidence  in  the  sediments  that  an  Appa- 
lachian river  flower  southwestward  through  the  Coosa  valley. 
This  would  also  have  brought  the  bulk  of  the  sediments  far- 
ther eastward  than  where  they  now  occur.  While  I  regard 
Johnson's  evidence  (op.  cit.)  as  conclusive  for  the  course  of 


3  Credner,  H.,  "  Die  Delten,"  Petermann  Geog.  Mitth.,  Erganzungs- 
heft  56,  pp.  1-74,  pi.  3,  1878. 

4  Grabau,  A.  W.,  Early  Paleozoic  Delta  Deposits  of  North  Amer- 
ica," Bull.   Geol.   Soc.  Am.,  vol.   24,  pp.   399-528,    113. 

B  Barrell,  J.,  idem.,  vol.  23,  pp.   377-446,   1912. 


22  Tuscaloosa  Formation  [220 

the  Tennessee  River  across  Walden  Ridge,  I  cannot  help 
believing  that  the  Cretaceous  ancestor  of  this  stream  at  the 
beginning  of  Tuscaloosa  time,  instead  of  making  the  sharp 
turn  to  the  northwest  at  Guntersville,  Alabama,  which  it  does 
at  present,  continued  southwestward  down  either  Brown  or 
Big  Spring  valleys  and  reached  the  sea  through  either  the 
Mulberry  or  Locust  fork  of  the  Warrior  River.  This,  how- 
ever, is  not  an  essential  part  of  my  argument  for  the  delta 
character  of  the  Tuscaloosa  formation,  since  there  was  obvi- 
ously at  that  time  a  stream  or  a  series  of  streams  draining  to 
the  southwest  and  engaged  in  removing  the  debris  of  the  long 
weathered  land  mass. 


SW  NE 


POTTSVILLE 


FIG.  2. 

Section   showing  relation   of   the  Tuscaloosa  deposits  to  those  of 
the  Eutaw  and   Selma  formations. 

I  do  not  wish  to  be  understood  as  ignoring  the  fact  that 
some  of  the  Tuscaloosa  deposits  are  sub-aerial  and  that  ori- 
ginally the  delta  deposits  probably  continued  inland  up  the 
valley  or  valleys  for  considerable  distances  as  continental  de- 
posits of  channels,  flood  plains  and  lakes.  The  antecedent 
meanders  of  the  present  streams  give  clear  evidence  of  con- 
ditions that  prevailed  on  the  Cumberland  peneplain  that  were 
suitable  for  the  formation  of  ox-bow  lakes.  There  must  have 
been  quiet  waters  in  the  delta  itself  in  certain  bayous  or 
possibly  lakes  like  lakes  Salvador,  Ponchartrain  and  Borgne 
of  the  present  Mississippi  delta  region.  Certainly  the  leaf- 
bearing  clays  near  Glen  Allen  and  Shirley's  Mill  in  Fayette 
County,  Alabama,  were  formed  in  such  quiet  bodies  of  water 
with  densely  wooded  shores. 

The  relations  of  the  Tuscaloosa  formation  emphasizes  its 
delta  character  as  is  shown  in  the  accompanying  textngure. 


221]  E.  W.  Berry  23 

The  Tuscaloosa  sands  grade  seaward  into  the  glauconitic 
sands  and  thinly  laminated  clays  of  the  Eutaw  formation 
which  contains  a  sparing  representation  of  the  marine  life 
of  the  time,,  which  must  have  been  in  part  at  least  contem- 
poraneous with  the  Tuscaloosa.  A  few  plants  in  the  near 
shore  transgressing  phase  have  been  collected  from  near 
Havana  in  Hale  County,  Alabama.  The  upper  Eutaw,  or 
Tombigbee  sand  member  I  regard  as  a  transgressing  deposit 
and  in  conformity  with  this  interpretation  it  contains  a  much 
better  marine  fauna  than  the  earlier  Eutaw  deposits.  Over- 
lying the  Eutaw  formation  is  the  Selma  chalk — an  argilla- 
ceous limestone  or  calcareous  clay  which  reaches  its  maximum 
thickness  in  the  same  region  as  does  the  Tuscaloosa  sands, 
namely  southwest  of  the  axis  of  the  Appalachian  land  mass. 
In  this  area  the  Selma  chalk  continues  upward  to  the  Eocene 
contact.  Its  outcrop  as  shown  on  the  accompanying  sketch 
map  is  almost  perfectly  lunate,  and  at  its  horns  both  to  the 
east  and  the  north  it  passes  over  into  sands.  The  Selma,  as 
shown  by  its  abundance  of  Ostracea  and  other  Mollusca  is  a 
shallow  water  deposit.  So  far  as  my  observation  goes  it  is 
entirely  destitute  of  drift  wood,  lignite  or  any  considerable 
sandy  beds  in  the  area  of  its  greatest  thickness  and  the  point 
that  I  wish  to  make  is  that  the  southwestern  drainage  that 
explains  the  character  of  the  Tuscaloosa  sediments  must  have 
been  reduced  to  a  minimum  or  become  practically  non-exist- 
ant  before  the  deposition  of  the  Selma  chalk.  The  prevailing 
direction  of  the  drainage  during  Selma  time  must  have  been 
to  the  southeast  and  northwest  in  order  to  explain  the  Eipley 
sands  in  those  regions  and  the  absence  of  any  except  the 
finest  terrigenous  materials  in  the  main  body  of  the  Selma 
chalk. 

Inferentially  if  the  Cretaceous  Tennessee  River  was  a  fac- 
tor in  the  building  of  the  Tuscaloosa  delta,  local  warping 
must  have  broken  its  continuity  with  the  Warrior  drainage 
and  started  it  toward  the  northwest  before  the  deposition  of 
the  Selma  chalk.  It  is  possible  that  this  may  have  been 
accomplished  without  local  warping  by  the  simple  clogging 


24  Mineralizers  in  Ore  Segregations  [222 

of  its  distributaries  as  a  result  of  their  own  loads  combined 
with  decreased  run  off.  This  set  of  factors  combined  with 
the  westward  tilting  that  resulted  in  the  Eipley  Cretaceous 
and  Midway  Eocene  seas  penetrating  up  the  Mississippi  val- 
ley as  far  as  southern  Illinois  is  sufficient  to  account  for  the 
observed  change,  of  course  assuming  that  there  has  been  such 
a  change.  This  may  be  compared  to  the  analogy  of  the  shift- 
ing of  the  present  Mississippi  delta  to  the  eastward  by  marine 
currents. 

The  remnants  of  heavy  gravels  of  Tuscaloosa  age  that  have 
been  traced  by  Wade  across  Tennessee  and  into  Kentucky 
appear  to  represent  the  gradual  migration  or  shifting  north- 
ward of  such  a  stream.  That  the  western  Highland  Eim 
of  Tennessee  is  a  middle  or  late  Tertiary  planation  of  pre- 
vailingly siliceous  rocks  by  the  Tennessee  River  in  its  lower 
northward  course  is  probably  true  but  hardly  within  the 
scope  of  the  present  brief  note. 


THE  ROLE  OF  MINERALIZERS  IN  ORE  SEGREGATIONS 
IN  BASIC  IGNEOUS  ROCKS 

By  JOSEPH  T.  SINGEWALD,  JR. 


Though  one  of  the  latest  groups  of  ore  deposits  to  be  defi- 
nitely recognized,  the  magmatic  segregations  were  firmly  es- 
tablished as  one  of  the  major  types  through  the  classic  work 
of  J.  H.  L.  Vogt  twenty-five  years  ago ;  and  it  has  been  gener- 
ally felt  by  economic  geologists  that  the  mode  of  formation 
of  these  deposits  was  so  clearly  understood  that  they  consti- 
tuted a  group  concerning  the  genesis  of  which  there  was  no 
further  question.  More  thorough  petrographic  studies  of 
many  examples  of  deposits  classed  with  the  magmatic  segre- 
gations and  metallographic  investigation  of  the  ores,  espe- 
cially during  the  last  decade,  have  accumulated  more  and  more 
evidence  to  show  that  mineralization  was  not  so  simple  and 
did  not  conform  strictly  to  the  conception  of  a  magmatic 
segregation  in  the  sense  in  which  that  term  is  generally 


223]  J.  T.  Sing ew aid  25 

thought  of.  The  time  has  arrived  for  a  definite  recognition 
of  these  discordant  data  and  a  remolding  of  our  conceptions 
in  harmony  with  them. 

The  term  magmatic  segregation  was  borrowed  by  the  eco- 
nomic geologist  from  the  petrographer  and  used  in  the  petro- 
graphic  sense.  Its  application  to  the  explanation  of  the 
genesis  of  certain  ore  deposits  seemed  very  plausible.  It  is 
a  matter  of  common  petrographic  knowledge  that  no  large 
body  of  igneous  rock  is  of  uniform  composition  and  that 
frequently  the  composition  of  a  portion  of  the  mass  departs 
widely  from  the  average.  Consequently  there  were  forces  at 
work  prior  to  or  during  the  consolidation  of  the  molten 
magma  which  caused  local  segregations  of  certain  of  its  con- 
stituents. The  nature  of  these  forces  has  long  been  a  matter 
of  discussion  and  speculation  but  unanimity  of  opinion  has 
not  been  attained  and  there  is  no  thoroughly  satisfactory 
explanation  of  the  process  which  is  known  as  a  magmatic 
segregation  or  differentiation.  The  usual  manifestation  of 
the  phenomenon  is  in  the  local  accumulation  of  the  more  basic 
constituents  of  the  magma. 

The  basis  for  the  application  of  this  process  as  an  explana- 
tion of  ore  genesis  rests  on  certain  other  observations  in  the 
field  of  petrography.  There  is  present  in  almost  all  igneous 
rocks  a  group  of  opaque  minerals,  occurring  as  accessory  con- 
stituents and  with  euhedral  forms,  the  most  common  repre- 
sentatives of  which  are  the  sulphides  of  iron,  frequently  cu- 
priferous, and  the  oxides  of  iron,  frequently  chromiferous  or 
titaniferous.  On  account  of  their  commonly  euhedral  forms, 
these  minerals  are  regarded  by  petrographers  as  the  earliest 
constituents  of  the  magma  to  crystallize.  Furthermore,  these 
minerals  are  concentrated  together  with  the  basic  silicates  in 
the  process  of  rock  differentiation. 

There  are  many  ore  deposits  world-wide  in  their  distribu- 
tion possessing  certain  common  characteristics,  among  which 
may  be  mentioned:  (1)  the  ore  minerals  consist  of  one  or 
more  of  the  accessory  opaque  minerals  common  to  igneous 
rocks;  (2)  the  enclosing  rock  is  always  an  igneous  rock  and 


26  Mineralizers  in  Ore  Segregations  [224 

usually  basic  in  composition;  (3)  the  gangue  minerals  of 
these  deposits  are  the  same  as  the  constituent  minerals  of 
the  enclosing  rock;  (4)  the* ore  body  frequently  passes  by 
gradual  transition  into  the  igneous  rock  by  a  decrease  in  the 
amount  of  the  ore  minerals  and  increase  in  the  amount  of 
the  silicates.  These  deposits  appeared  to  be  an  integral  part 
of  the  igneous  rock  in  which  they  are  found  and  to  represent 
an  extreme  facies  of  the  product  of  rock  differentiation,  and 
consequently  were  established  as  an  independent  group  of  ore 
deposits  to  which  the  name  magmatic  segregation  was  applied. 
The  group  was  subdivided  by  Vogt  into  three  divisions  ac- 
cording as  the  metal  occurs  in  the  native,  oxidic  or  sulphidic 
form.  Segregations  of  native  metals  as  primary  ore  deposits 
are  of  little  economic  importance,  but  the  placers  derived 
from  such  of  native  platinum  in  the  Urals  are  our  principal 
source  of  that  metal.  Segregations  of  oxidic  ores  are  our 
only  source  of  chrome  ores,  include  countless  deposits  of 
titaniferous  iron  ores,  and  important  deposits  of  non-titan- 
iferous  iron  ores.  Segregations  of  sulphidic  ores  include  the 
nickeliferous  and  supriferous  pyrrhotites  and  probably  a  few 
copper  sulphide  deposits. 

The  metallic  content  of  the  segregations  of  the  native 
metals  is  usually  rather  sparsely  disseminated  through  the 
rock,  and  on  account  of  the  few  examples  and  their  minor 
importance,  the  propriety  of  regarding  the  metal  as  a  segre- 
gation and  product  of  crystallization  from  a  molten  magma 
has  been  little  questioned.  The  segregations  of  oxidic  ores 
usually  occur  well  within  the  igneous  mass,  and  there  are  so 
many  admirable  illustrations  of  gradation  from  ore-mineral 
bearing  rock  to  ore  body  that  no  particular  significance  has 
been  attached  to  the  observation  in  a  number  of  instances 
that  the  ore  minerals  are  later  than  the  silicates,  and  the 
conception  of  a  segregation  and  solidification  from  a  molten 
magma  has  been  rarely  challenged.  The  position  of  the  sul- 
phidic deposits  has,  however,  been  somewhat  dubious  from 
the  start.  They  tend  to  occur  on  the  periphery  of  the  ig- 
neous mass,  the  sulphides  often  penetrate  into  the  wallrock, 


225]  J.  T.  Singewald  27 

it  was  early  recognized  that  in  part  at  least  the  sulphides  are 
distinctly  later  than  the  rock-forming  silicates,  and  the  rock 
itself  has  frequently  undergone  considerable  alteration. 
Many  geologists  have  consequently  insisted  on  .regarding 
them  as  hydrothermal  deposits.  A  most  interesting  feature 
of  the  controversy  over  the  genetic  position  of  these  sulphidic 
ores  has  been  that  the  largest  and  most  important  example, 
the  nickel  deposits  of  Sudbury,  Ontario,  which  has  been  cited 
by  the  advocates  of  the  magmatic  origin  as  a  typical  illustra- 
tion of  that  type,  is  one  to  which  most  serious  objection  has 
been  raised  by  those  contending  for  a  hydrothermal  origin. 

In  view  of  the  departures  manifested  by  these  deposits 
from  the  conceptions  based  on  purely  petrographic  pheno- 
mena and  concepts,  it  is  interesting  to  see  how  the  problem 
has  been  handled  in  four  of  the  leading  recent  textbooks  on 
ore  deposits.  The  four  selected  are:  R.  Beck,  Die  Erzlager- 
statten,  1909  (3rd  edition) ;  Beyschlag-Krusch-Vogt,  Die 
Lag erstdtten  der  nutzbaren  Mineralien  und  Gesteine,  1910; 
W.  Lindgren,  Mineral  Deposits,  1913;  L.  DeLaunay,  Giles 
Mineraux  et  Metalliferes,  1913. 

Beck,  in  denning  magmatic  segregations,  says :  "  In  many 
instances  there  took  place  in  the  rock  either  before  or  during 
solidification  from  the  molten  state  a  concentration  of  the 
ores  into  irregular  masses.  ...  In  spite  of  the  concentra- 
tion into  a  limited  space,  the  ores  of  such  deposits  remain, 
what  they  as  scattered  particles  in  the  rocks  in  question  are, 
namely  accessory  constituents."  Commenting  on  Vogt's  ob- 
servation that  in  certain  of  the  Swedish  and  Norwegian  titani- 
ferous  iron  ore  deposits  the  silicates  formed  first  and  then 
the  titanif erous  magnetite,  he  says,  "  these  are  departures 
from  the  rule  otherwise  prevailing  for  eruptive  rocks  that  the 
iron  ores  belong  to  the  earliest  minerals  to  separate."  In 
all  chrome  deposits  for  which  he  cites  the  sequence  of  crys- 
tallization, the  chromite  is  the  earliest  constituent.  Of  the 
sulphidic  deposits,  on  the  other  hand  he  says,  "  The  strict 
proof  of  segregation  from  a  molten  magma  cannot  always  be 
established  with  the  same  degree  of  sharpness.  .  .  .  For  a 


28  Mineralizers  in  Ore  Segregations  [226 

great  many  occurrences,  which  numerous  authors  consider  a 
direct  segregation  from  eruptive  rocks,  one  must  at  least  con- 
sider probable  a  later  secondary  recrystallization  of  the  ores 
by  aqueous  processes  which  brought  about  a  partial  migration 
and  an  impregnation  of  the  wallrock."  These  conclusions 
are  based  largely  on  his  own  work  in  1902  and  1903  on  the 
deposits  of  nickeliferous  pyrrhotite  and  chalcopyrite  at  Soh- 
land  in  Saxony,  where  he  found  ore  deposition  took  place  by 
replacement  subsequent  to  the  hydrothermal  alteration  of  the 
rock,  though  he  believes  both  followed  immediately  after  its 
solidification. 

"With  the  exception  of  the  treatment  of  the  sulphidic  ores, 
the  position  of  Beyschlag,  Krusch  and  Vogt  is  similar  to  that 
taken  by  Beck.  Their  ideas  are  of  course  largely  those  devel- 
oped by  Vogt.  Their  conception  of  the  genesis  of  these  ore 
deposits  is  that,  "  In  the  same  manner  in  which  larger  masses 
of  mica  and  feldspar  can  collect  out  of  a  granite  magma, 
segregation  of  ores  can  take  place,  as  for  example  of  mag- 
netite, titaniferous  magnetite,  chromite  and  pyrrhotite,  in 
such  igneous  rocks  which  normally  carry  these  ores  as  acces- 
sory constituents."  They  call  attention  to  the  fact  that  the 
ore  minerals  followed  by  the  iron-magnesium  silicates  are 
the  earliest  constituents  to  crystallize  in  most  eruptive  rocks 
and  they  are  also  the  constituents  that  migrate  in  magmatic 
differentiation.  Magmatic  segregation  is  distinguished  from 
ore  deposition  in  which  mineralizers  participate  as  follows: 
"  The  genetic  difference  consists  essentially  therein  that  the 
magmatic  segregations  result  from  a  single  differentiation 
process  of  the  magma,  whereas  in  the  case  of  the  pneumato- 
lytic  and  contact  metamorphic  deposits  the  metallic  content 
originally  belonging  to  the  magma  is  transferred  to  an  aque- 
ous or  gaseous  solution  and  later  deposited  from  this  through 
new  processes."  Though  in  most  cases  the  two  groups  are 
considered  as  sharply  differentiated,  they  admit  that  occa- 
sionally there  are  intermediate  stages  in  which  magmatic  dif- 
ferentiation is  accompanied  by  pneumatblytic  or  pneumato- 
hydatogenetic  processes.  They  definitely  state  that  the  chrome 


227]  J.  T.  Singewald  29 

ores  crystallized  out  of  a  magma  and  that  the  forma- 
tion of  the  titanif erous  magnetites  "  depends  on  a  pure  mag- 
matic  separation,  not  accompanied  by  special  pneumatolytic 
processes,"  and  that  the  process  differs  from  ordinary  rock 
differentiation  only  in  that  it  has  proceeded  much  further. 
The  characteristic  association  of  more  or  less  titanomagnetite 
with  the  sulphides  is  taken  to  indicate  a  genesis  for  the  latter 
ores  analogous  to  that  of  the  titaniferous  magnetites.  In 
further  substantiation  of  the  magmatic  origin  of  the  sul- 
phides is  the  statement  that  secondary  alterations  such  as 
uralitization  before  ore  deposition  or  contemporaneous  with 
it  has  not  in  general  occurred.  They  emphasize  the  fluidity 
of  the  molten  sulphides  and  the  consequent  power  of  pene- 
tration into  minute  crevices  and  cracks  and  have  proposed  a 
subdivision  of  injected  sulphide  deposits,  which  represents 
intrusions  of  molten  sulphides  into  the  country  rock.  In 
such  an  interpretation  of  a  number  of  the  most  important 
examples  included  under  this  subdivision,  however,  they  stand 
almost  alone.' 

The  deposits  under  discussion  are  classed  by  Lindgren  as 
"  Mineral  deposits^Jefmed  by  concentration  in  molten  mag- 
mas," concerning  which  he  says :  "  Certain  kinds  of  mineral 
deposits  form  integral  parts  of  igneous  rock  masses  and  per- 
mit the  inference  that  they  have  originated,  in  their  present 
form,  by  processes  of  differentiation  and  cooling  in  molten 
magmas/'  Of  the  oxidic  ores  he  says  chromite  appears  in  all 
cases  to  be  the  earliest  consolidated  constituent,  but  that  the 
titaniferous  iron  ores  have  as  a  rule  crystallized  after  the 
silicates ;  but  he  says  further  about  the  latter :  "  Petrographic 
research  has  long  ago  shown  that  ilmenite  with  magnetite  is 
one  of  the  earlier  products  of  consolidation  in  magmas  and 
is  contained  in  almost  all  diabases,  basalts,  and  gabbros.  .  .  . 
The  larger  masses  of  ilmenite  are  simply  facies  of  the  rock 
itself  produced  by  concentration  from  the  same  magma." 
Lindgren's  position  concerning  the  sulphides  is  almost  identi- 
cal with  that  of  Beyschlag,  Krusch  and  Vogt,  as  is  evidenced 
by  such  statements  as,  "  Some  of  the  magmatic  sulphide 


30  Mineralizers  in  Ore  Segregations  [228 

deposits  are  simple  basic  rocks  abnormal  in  containing  much 
pyrrhotite,  chaicopyrite  and  pentlandite,"  and,  "  Some  de- 
posits in  which  the  ore  consists  mainly  of  solid  pyritic 
minerals  present  features  which  can  hardly  be  explained 
otherwise  .than  by  actual  injection  of  molten  sulphides,"  in 
spite  of  his  admission  that  "  on  the  whole  the  sulphides  are 
the  latest  products  crystallized."  In  reply  to  the  advocates 
of  a  hydrothermal  origin  for  certain  of  these  deposits,  %  he 
charges  them  with  having  confused  secondary  changes  with 
primary  deposition. 

DeLaunay's  treatment  of  these  deposits  differs  consider- 
ably from  any  of  the  preceding.  The  first  five  divisions  of 
his  genetic  classification  of  ore  deposits  are  the  following: 

1.  Gites  d'Inclusions. 

2.  Gites  de  Segregation. 

3.  Gites  de  Depart  Immediat  ou  de   Segregation  Peri- 

pherique  Sulfuree. 

4.  Gites  de  Contact  du  Type  Banat. 

5.  Impregnations  Diffuses  de  Profundeur  (includes  amas 

pyriteux) . 

"  Deposits  of  inclusions  are  those  where  a  useful  mineral 
occurs  in  an  igneous  rock  in  the  same  relation  as  the  other 
constituent  elements."  This  division  is  of  theoretic  rather 
than  practical  importance,  and  includes  only  native  metals 
and  oxides  present  as  normal  accessory  constituents  of  an 
igneous  rock  without  the  intervention  of  mineralizers.  The 
segregation  deposits,  he  says,  might  be  regarded  as  having 
been  effected  without  intervention  of  volatile  constituents, 
nevertheless  the  general  opinion  today  is  that  water  and  pro- 
bably other  mineralizers  have  played  a  role,  though  he  con- 
siders them  formed  in  a  medium  poor  in  mineralizers.  The 
ores  are  native  metals  and  oxides.  The  Gites  de  Depart 
Immediat,  or  peripheral  sulphide  seregations,  he  says,  have 
usually  been  considered  examples  of  true  segregations  which 
differ  from  the  internal  oxidic  segregations  by  their  position 
and  nature.  DeLaunay  believes  it  necessary,  however,  to 


229]  J.  T.  Singeiuald  31 

separate  them  entirely  from  the  true  segregations,  for  there 
has  been  a  concentration  of  sulphides  not  only  in  the  rock 
but  at  its  contact,  and  they  appear  to  him  to  be  a  close 
parent  to  contact  metamorphic  deposits  which  are  formed 
when  the  wallrock  is  a  limestone.  They  represent  a  type  of 
ore  deposition  in  which  mineralizers  are  more  abundant  and 
active  than  in  the  preceding.  The  very  close  relation  postu- 
lated between  these  deposits  and  typical  contact  metamorphic 
deposits  indicates  clearly  that  he  does  not  look  upon  them 
as  representing  a  crystallization  from  a  molten  state.  The 
mineralization  of  the  last  group  is  analogous  to  that  of  the 
fourth,  the  types  of  deposits  included  under  it  being  formed 
where  the  country  rock  is  other  than  a  carbonate  rock.  It 
includes  most  of  the  deposits  classified  by  Beyschlag,  Krusch 
and  Vogt  as  injected  sulphide  deposits.  There  are  no  sharp 
lines  of  demarcation  between  these  groups,  as  DeLaunay 
recognizes  a  complete  transition  from  purely  igneous  deposits 
to  hydrothermal  veins  and  that  in  some  instances  it  is  difficult 
to  decide  between  fusion  and  solution. 

In  an  attempt  to  settle  some  of  the  doubtful  points  con- 
cerning the  mode  of  formation  of  the  sulphidic  ores  usually 
classed  as  magmatic  segregations,  C.  F.  Tolman,  Jr.  and  A. 
F.  Eogers  of  Stanford  University  have  just  published  the 
results  of  a  very  comprehensive  petrographic  and  metallo- 
graphic  investigation  of  those  ores  as  a  monograph  entitled 
"  A  Study  of  the  Magmatic  Sulfid  Ores."  They  formulate  a 
number  of  statements  which  they  find  applicable  to  all  of  the 
deposits  studied,  the  most  significant  of  which  are : 

1.  The  first  minerals  to  form  are  olivine,  the  pyroxenes 
and  the  feldspars. 

2.  Magmatic  alteration  of  the  silicates  often  takes  place 
prior  to  the  formation  of  the  ore  minerals.     The  most  com- 
mon change  is  that  of  pyroxene  to  hornblende,  but  easily 
distinguishable  from  the  hydrothermal  process  of  uralitiza- 
tion. 

3.  The  ores  replace  the  silicate  minerals  but  without  re- 
action rims. 


32  Mineralizers  in  Ore  Segregations  [230 

4.  The  ores  are  introduced  one  after  another  in  the  fol- 
lowing invariable  sequence:  (1)  magnetite  and  ilmenite,  (2) 
pyrrhotite,    (3)    pentlandite,    (4)    chalcopyrite.     There  is   a 
certain  amount  of  replacement  of  the  earlier  ore  minerals  by 
the  later  ones. 

5.  Hydrothermar  alteration  is  distinctly  later  than  the 
period  of  ore  deposition. 

These  data  of  observation  lead  them  to  a  theory  of  genesis 
more  nearly  analogous  to  that  of  DeLaunay  than  any  of  the 
others  mentioned  above.  The  fact  that  the  ore  minerals 
replace  the  silicates  without  the  formation  of  metallic  sili- 
cates by  reaction  is  interpreted  to  mean  that  the  ores  were 
not  introduced  in  a  molten  state  but  that  the  same  agency 
that  brought  in  the  sulphides  removed  the  dissolved  silicates, 
indicating  the  presence  of  active  mineralizers.  The  altera- 
tion of  pyroxene  to  hornblende  is  further  evidence  of  the 
presence  of  mineralizers.  Consequently  they  conclude  that 
mineralization  took  place  at  a  temperature  below  the  melting 
point  of  the  ores  and  that  they  were  held  in  solution  through 
the  agency  of  mineralizers.  On  the  other  hand,  that  ore  de- 
position took  place  under  conditions  different  from  those  of 
non-magmatic  high  temperature  deposits  is  shown  by  the 
absence  of  the  secondary  silicates  characteristic  of  ordinary 
pneumatolytic  and  hydrothermal  processes,  or  that  where 
present  they  belong  to  a  distinctly  later  period.  They  con- 
clude, that  the  magmatic  ores  "have  been  introduced  at  a 
late  magmatic  stage  as  a  result  of  mineralizers." 

The  direct  evidence  presented  by  Tolman  and  Eogers  is 
derived  from  the  sulphide  deposits,  but  the  presence  of  a 
greater  or  less  quantity  of  titaniferous  magnetite  in  these,  and 
numerous  references  in  •  the  literature  to  the  silicates  pre- 
ceding the  ores  in  order  of  crystallization  in  deposits  of  titan- 
iferous magnetite,  led  them  to  infer  that  the  same  observa- 
tions and  same  conclusions  apply  equally  well  to  the  oxidic 
ores.  My  own  experience  with  the  titaniferous  magnetites 
corroborates  the  correctness  of  this  inference.  The  relations 
between  ore  minerals  and  silicates  figured  and  described  for  the 


231]  J.  T,  Singewald  33 

sulphide  ores  are  repeatedly  duplicated  in  thin  sections  and 
polished  sections  from  all  occurrences  of  titaniferous  iron 
ores  in  the  United  States.  Titaniferous  magnetite  later  than 
the  silicates  and  replacing  them  is  seen  in  nearly  every  section 
of  the  ores,  though  many  of  the  contacts  of  the  two  sets  of 
minerals  show  what  L.  C.  Graton  and  D.  H.  McLaughlin 
have  recently  termed  mutual  boundaries,  that  is,  boundaries 
that  give  little  evidence  of  the  sequence  of  the  minerals. 
Only  rarely  is  there  unmistakable  evidence  of  primary  sili- 
cates distinctly  later  than  the  ore.  The  replacement  of  the 
silicates  by  the  ore  has  not  been  accompanied  by  the  forma- 
tion of  reaction  silicates  and  in  several  instances  hornblendi- 
zatioirhas  preceded  the  deposition  of  ore,  phenomena  in  har- 
mony with  the  nature  of  mineralization  in  the  case  of  the 
sulphide  ores.  If  segregation  takes  place  without  the  interven- 
tion of  mineralizers,  one  might  expect  the  deposit  at  Iron 
Mountain,  Wyoming,  to  afford  such  an  example.  The  ore 
body  there  occurs  as  an  almost  pure  mass  of  titaniferous 
magnetite  .cutting  the  anorthositic  country  rock  as  sharply 
as  any  igneous  dike  ever  pictured.  Yet  the  numerous  oliviny 
crystals  which  occur  locally  in  the  ore  are  rounded  and  em- 
bayed without  the  formation  of  reaction  silicates  in  exactly 
the  same  manner  as  in  other  occurrences.  The  deposit  sug- 
gests an  injection  from  a  basic  magma  analogous  to  a  peg- 
matite from  a  more  acidic.  In  other  cases,  particularly  at 
Grape  Creek,  Colorado,  the  introduction  of  ore  has  been 
accompanied  by  alteration  of  the  feldspar  so  that  the  mag- 
netite is  separated  from  it  by  a  band  of  hornblende,  indi- 
cating greater  than  usual  activity  of  mineralizers.  The  Min- 
nesota deposits  conform  for  the  most  part  to  the  general  rule 
that  the  ore  is  later  than  the  silicates  and  afford  some  exam- 
ples of  hornblendization  preceding  or  contemporaneous  with 
ore  deposition,  but  also  instances  of  feldspar  and  pyroxene 
later  than  ore. 

An  excellent  example  of  an  iron  ore  deposit  in  a  basic 
igneous  rock  giving  unmistakable  evidence  of  active  partici- 
pation by  mineralizers  in  the  formation  of  the  ore  is  afforded 

3 


34  Mineralizers  in  Ore  Segregations  [232 

by.  the  Tofo  deposit  north  of  Coquimbo,  Chile,  being  worked 
by  the  Bethlehem  Steel  Company.  This  consists  of  a  large 
mass  of  comparatively  pure  magnetite  forming  the  top  of  a 
hill  on  the  east  side  of  the  coast  range  and  occurring  within  a 
large  area  of  gabbro  rock.  The  igneous  mass  has  undergone 
considerable  differentiation  and  various  rock  types  are  repre- 
sented in  the  vicinity  of  the  ore  body  from  highly  feldspathic 
to  almost  pure  ferromagnesian  silicate  rocks,  some  of  which 
occur  as  dikes.  The  broader  relations  of  the  ore  body  are 
such  as  to  suggest  at  once  a  magmatic  segregation;  but,  at 
the  same  time,  there  are  many  features  that  suggest  pneuma- 
tolysis.  Adjacent  to  the  ore,  there  are  numerous  stringers  of 
magnetite  in  the  country  rock,  many  of  them  of  no  greater 
thickness  than  a  knife  blade,  which  traverse  it  in  such  a 
way  as  to  preclude  the  entrance  of  molten  oxides  and  that  can 
be  explained  only  on  the  basis  of  the  high  liquidity  at  lower 
temperature  that  would  be  imparted  by  the  presence  of 
abundant  mineralizers. 

The  argument  for  the  participation  of  mineralizers  in  the 
formation  of  magmatic  deposits  is  a  plausible  one  ,also  from 
a  general  standpoint  of  ore  genesis.  Processes  in  nature 
representing  different  stages  of  a  sequence  from  a  given 
starting  point  are  not  usually  separated  by  a  hiatus.  It  is 
generally  accepted  today  that  igneous  magmas  are  the  pri- 
mary sources  of  the  metals  and  modern  genetic  classifications 
group  ore  deposits  according  to  their  position  or  relation  to 
the  original  sources.  It  has  been  customary,  however,  to- 
draw  a  sharp  line  between  one  group  of  deposits  which  it  was 
held  segregated  from  the  molten  magma  and  solidified  with 
it,  and  such  groups  as  represented  deposition  of  material 
extracted  from  the  magma  by  mineralizers  and  constituting 
the  pneumatolytic  and  hydrothermal  deposits.  DeLaunay's 
classification  recognizes  no  such  hiatus  in  the  sequences  of 
mineralization,  but  postulates  a  gradually  increasing  partici- 
pation of  mineralizers  and  hence  a  gradual  gradation  from 
one  stage  to  the  next.  It  goes  even  a  step  further  and  indi- 


233]  J.  T.  Singewald  35 

cates  that  concentration  of  the  metallic  content  of  a  magma 
to  the  extent  necessary  to  form  important  ore  bodies  takes 
place  only  when  the  necessary  migration  of  the  metals  is 
aided  by  the  presence  of  mineralizers.  Eor  the  only  group 
recognized  by  him  in  which  mineralizers  did  not  participate 
in  ore  deposition,  his  gites  d' inclusions,  contain  no  deposits 
of  economic  importance;  and  it  is  only  in  his  next  group, 
in  which  mineralizers  begin  to  play  a  part,  that  important 
ore  deposits  begin  to  be  represented.  There  have  been  two 
lines  of  thought  seeking  to  explain  ore  genesis,  the  one  repre- 
sented by  the  French  school  which  has  always  emphasized 
the  role  of  mineralizers,  and  the  other  by  the  American  and 
German  economic  geologists  who  have  tended  to  draw  the 
sharp  line  of  demarcation  between  the  magmatic  deposits  and 
the  non-magmatic.  The  participation  of  the  latter  group  has 
so  greatly  preponderated  over  that  of  the  former  during  the 
last  quarter  century  in  the  development  of  the  science  of 
economic  geology  that  the  views  of  the  French  school  have 
often  been  completely  overshadowed  and  have  not  received 
the  attention  they  merit.  The  monograph  by  Tolman  and 
Rogers  will  serve  to  establish  among  American  economic  geol- 
ogists the  ideas  embodied  in  the  conceptions  of  the  French 
school.  It  is  hoped  that  this  survey  of  the  problem  and  the 
corroborative  evidence  contributed  in  the  case  of  the  iron 
ores  will  serve  the  same  purpose.  One  cannot  help  but  feel 
that  a  new  study  of  the  chrome  ores  with  this  interpretation  in 
mind  would  place  them  in  harmony  with  it.  As  their  case 
now  stands,  they  seem  to  be  an  exception  and  to  represent  a 
direct  segregation  as  the  first  product  of  crystallization  from 
a  molten  magma. 


36  Environment  of  Tertiary  Marine  Faunas       [234 


THE  ENVIRONMENT   OF   THE   TERTIARY  MARINE 
FAUNAS   OF  THE  ATLANTIC   COASTAL   PLAIN 

By  JULIA  A.  GARDNER 


The  Miocene  and  Pliocene  deposits  of  the  Atlantic  Coastal 
Plain  have  now  been  mapped  in  detail  from  New  Jersey  to 
North  Carolina  and  the 'contained  faunas,  which  are  prolific 
and  varied,  have  been  rather  fully  described.1 

The  following  formations  have  been  recognized  in  the 
Middle  Atlantic  region : 

Maryland  Virginia  North  Carolina 

Pliocene :  "Waccamaw 

Yorktown         Yorktown-Duplin 

,   St.  Mary's         St.  Mary's         St.  Mary's 
Miocene:     J  \  J  J 

Cnoptank 

Calvert  Calvert 

All  of  these  formations  contain  extensive  molluscan  faunas 
and  very  large  collections  have  been  available  for  study  and 
comparison.  An  idea  of  the  richness  of  these  faunas  may 
be  obtained  from  the  following  census  of  the  faunas  of  the 
respective  formations : 

No.  of  species      in  genera 

Waccamaw 325-335  130 

Yorktown 364-378  143 

Duplin 420-431  154 

St.  Mary's 326-344  129 

Calvert  .  80-83  50 


1  The  more  recent  literature  includes  the  following  : 
Whitfield,  R.  P.,  Hon.  U.  8.  Geol.  Survey,  vol.  xxiv,  1894. 
Clark,  Martin,  Glenn  and  others,  Miocene  vol.,  Md.  Geol.  Survey, 

1904. 
Gardner,  J.  A.,  "The  Miocene  and  Pliocene  Faunas  of  Virginia 

and  North   Carolina,"   Prof.  Paper  U.  S.  Geological   Survey. 

(In  press.) 


235]  J.  A.  Gardner  37 

These  faunas  are  exceedingly  interesting,  not  only  because 
of  their  diversity  and  the  remarkable 'development  of  certain 
groups,  but  also  because  of  the  light  they  shed  on  the  physical 
conditions  under  which  they  lived.  In  the  following  notes, 
which  are  based  on  the  study  of  compiled  tables  of  both  recent 
and  fossil  forms,  an  attempt  is  made  to  summarize  the  proba- 
ble physical  conditions  indicated  by  this  study. 

Any  attempt  to  reconstruct  bottom  conditions  in  the  ancient 
seas  must  of  necessity  be  based  upon  data  so  meagre  and  so 
inaccurate  that  any  hope  of  obtaining  absolute  values  is  vain, 
and  yet  it  does' seem  worth  while  to  occasionally  gather  the 
imperfect  knowledge  available  and  to  try  to  interpret  it. 
Errors  do,  to  a  certain  extent,  neutralize  one  another  and 
within  certain  limits  general  tendencies  and  relative  values 
can  be  given  with  a  very  considerable  degree  of  assurance. 

Over  800  species  have  been  determined  from  the  Miocene 
and  Pliocene  of  Virginia  and  North  Carolina  and  of  these 
approximately  20  per  cent,  persist  into  the  recent  faunas. 
Certainly  a  number  so  large  as  this  ought  to  give  a  fairly  true 
line  upon  general  temperature  and  bathymetric  conditions  in 
the  middle  and  later  Tertiaries. 

It  may  be  well  to  consider  the  main  sources  of  error  before 
giving  the  conclusions  which  they  modify. 

A.    SOURCES  OF  ERROR  IN  THE  DATA  UPON  THE  TERTIARY 

FAUNAS. 

1.     Errors  in  determination. 

This  is  one  of  the  least  important.  The  greater  part  of 
the  work  upon  the  faunas  in  question  has  been  done  by  less 
than  half  a  dozen  students  and  the  same  collections,  for  the 
most  part,  have  been  used  for  reference.  Consequently  the 
determinations,  whether  accurate  or  inaccurate,  are  fairly  con- 
sistent. Furthermore,  if  two  forms  are  so  much  alike  that 
there  is  a  question  as  to  their  identity,  a  similarity  of  envir- 
onmental conditions  is  implied,  even  though  the  differences 
may  later  prove  to  be  specific. 


38  Environment  of  Tertiary  Marine  Faunas       [236 

2.     A  mechanical  sorting  of  the  shells. 

This  is  a  much  more  serious  error  and  one  which  it  is  im- 
possible to  eliminate.  One  of  the  most  interesting  phases 
of  in-shore  marine  life  is  the  dissimilarity  in  the  dredge  hauls 
within  a  limited  area.  The  in-shore  currents  are  quite  suffi- 
cient to  materially  affect  the  character  of  the  bottom  and  the 
distribution  of  the  algal  growth  and  thus  to  limit  the  range 
of  a  considerable  number  of  species,  particularly  the  vege- 
table feeders.  Unfortunately,  almost  all  such  ecologic  varia- 
tions have  been  washed  away.  Not  only  have  near-by  but 
distinct  assemblages  due  to  slight  differences  in  environmental 
conditions  been  commingled  but  dead  shells  have  been  washed 
down  from  the  river  mouths  and  up  from  the  off-shores  and 
mixed  together  in  a  heterogeneous  ensemble.  The  hard  parts 
of  the  smaller  species,  many  of  which  constitute  an  important 
item  in  the  diet  of  various  fishes  may  be  carried  for  indefinite 
distances  beyond  their  normal  habitat  before  being  laid  down 
in  their  final  resting  place.  In  recent  faunas  extra-limital 
shells  are  usually  so  badly  worn  that  their  distant  origin  may 
be  surmised  but  in  the  fossil  forms  it  is  much  more  difficult 
to  isolate  them  by  this  method.  It  is,  however,  reasonable  to 
suppose  that  forms  occurring  in  any  considerable  abundance 
are  indigenous  to  the  fauna  but  inferences  made  from  the 
presence  of  only  one  or  two  individuals  should  be  guarded. 

B.     SOURCES  or  ERROR  IN  THE  DATA  UPON  THE  EECENT 

FAUNAS. 

1.    Errors  in  determination. 

These  are  much  more  frequent  in  the  Recent  collections 
than  in  the  fossil  because  the  work  has  extended  over  a  much 
greater  time  and  the  personal  element  is  much  more  conspicu- 
ous. However,  errors  in  the  determination  of  the  fossils  are 
frequently  parallel  to  those  of  the  Recent  faunas  so  that  the 
final  results  are  not  always  affected.  The  tendency  in  the 
Recent  work  is  towards  an  increasingly  finer  distinction  of 
species  so  that  the  ranges  are  becoming  more  and  more  re- 


237]  J*  A.  Gardner  39 

stricted.  This  is  especially  true  in  certain  families.  In  a 
recent  zoogeographic  study  of  the  West  Coast  Pyrammidelli- 
dae  10  faunal  zones  were  differentiated.2  The  three  most 
populous  were  the  Oregonic  with  70  species,  the  Californic 
with  164  and  the  Mazatlanic  with  75.  However,  only  11 
species  common  to  the  Oregonic  and  Californic  were  recog- 
nized and  only  2  common  to  the  Californic  and  Mazatlanic. 
No  refined  study  such  as  this  has  ever  been  made  upon  any 
of  the  East  Coast  molluscs,  but  when  it  is  done  the  number 
of  species  will  doubtless  be  greatly  increased  and  their  ranges 
greatly  diminished.  The  fossil  forms  can  then  be  interpreted 
in  terms  of  the  Eecent  with  an  accuracy  and  a  detail  far  in 
advance  of  anything  that  is  possible  at  present.  The  knowl- 
edge of  the  Tertiary  ecology  may  approximate  the  Recent 
but  it  can  never  go  beyond  it. 

2.     The  limited  number  of  dredging  records. 

Not  only  are  the  stations  relatively  few  in  number  but 
they  are  so  grouped  that  there  are  long  stretches  which  have 
not  yet  been  touched.  The  attempt  has  been  made,  however, 
to  cover  the  critical  areas,  such  as  that  of  the  Florida  coast, 
Hatteras  and  Woods  Hole.  The  New  England  fauna  is  well 
known  in  a  general  way  and  extensive  collections  have  been 
made  through  the  'Gulf  and  the  West  Indies  by  the  Blake 
and  the  Albatross.  A  very  short  but  significant  report  is  that 
of  Bartsch  and  Henderson  upon  a  two  days'  collecting  trip 
off  Chincoteague  Island  on  the  Virginia  coast  for  the  pur- 
pose of  determining  the  extent  of  overlap  of  the  southern 
fauna.3  The  latest  of  the  larger  reports,  that  upon  the 
Woods  Hole  region  is  by  far  the  most  satisfactory  excepting 
that  it  covers  an  area  so  restricted  and  so  little  diversified. 
The  arrangement,  however,  is  excellent  for  an  ecologic  study, 
the  dead  shells  are  isolated  from  the  living  and  the  young 


2  Bartsch,  P.,  1912,  Proc.  u.  S.  National  Museum,  vol.  42,  p.  299. 

3  Bartsch  and  Henderson,  1914,  Proc.  U.  8.  Nat.  Mus.,  vol.  47,  pp. 
411-421. 


40          Environment  of  Tertiary  Marine  Faunas       [238 

from  the  adult,  the  number  of  specimens  is  given  and  the  data 
upon  depth,  temperature,  salinity,  etc.,  is  complete  and  accu- 
rate. The  bathymetric  distribution  of  most  of  the  southern 
stations  is  unfortunate  for  those  interested  in  determining 
the  limits  in  depth  of  the  littoral  fauna.  Very  little  shore 
dredging  has  been  done  and  there  are  very  few  records  from 
less  than  10  fathoms.  A  number  of  unusually  rich  hauls  were 
made  off  Hatteras  between  15  and  25  fathoms.  The  49  and 
63  fathom  stations  include  in  addition  to  the  native  fauna  a 
considerable  number  of  young  or  more  or  less  worn  shells 
referrable  to  the  more  abundant  species  in  the  lesser  depths 
but  in  the  great  majority  of  records  these  fortuitous  shells 
have  not  been  isolated.  However,  the  general  relationships 
which  come  out  of  an  interpretation  of  the  recent  elements  in 
the  fossils  faunas  are  probably  true,  even  though  the  data 
upon  which  the  results  are  based  is  woefully  inadequate. 

Five  formations  have  been  recognized  in  the  Miocene  and 
Pliocene  of  Virginia  and  North  Carolina, — the  Calvert,  St. 
Mary's  and  Yorktown  in  Virginia  and  the  Yorktown,  Duplin 
and  Waccamaw  in  North  Carolina.  The  Yorktown  and  Du- 
plin were  probably,  for  the  most  part,  synchronous  though 
laid  down  in  separate  basins.  Approximately  65%  of  the 
species  common  to  the  Calvert  and  Recent  faunas  have  been 
reported  from  north  of  Hatteras,  the  limit  of  range  of  many 
of  the  northern  and  of  the  southern  forms;  54%  of  the  St. 
Mary's;  46%  of  the  Yorktown;  35%  of  the  Duplin,  and 
36%  of  the  Waccamaw.  Factors  other  than  temperature  have 
modified  somewhat  the  figures  for  the  Duplin  and  Waccamaw, 
for  there  is  no  reason  to  suppose  that  the  Waccamaw  sea  was 
not  quite  as  warm  as  the  Duplin. 

The  break  between  the  late  Oligocene  and  the  early  Mio- 
cene in  the  Southern  Atlantic  states  is  one  of  the  sharpest  in 
the  stratigraphic  succession  of  the  Cenozoic.  The  Oligocene 
has  not  been  recognized  either  in  Virginia  or  North  Caro- 
lina but  the  early  Miocene  fauna  is  similar  in  general  charac- 
ter wherever  it  occurs  along  the  East  Coast.  Twenty  species 


239]  J.  A.  Gardner  41 

from  the  Calvert  of  Virginia,  approximately  12l/2%  of  the 
entire  fauna,  persist  into  the  Eecent  and  furnish  consistent 
evidence  of  environmental  conditions  during  Calvert  Times. 
The  depth  of  the  waters  in  which  they  live  did  not,  in  all 
probability,  exceed  20  or  25  fathoms.  The  temperature  was 
perceptibly  lower  than  that  of  any  other  of  the  middle  or 
late  Tertiary  faunas  of  that  region.  The  bottom  was  prob- 
ably soft,  dominaritly  mud,,  with  a  mixture  of  sand.  At 
least  a  portion  of  the  shore  must  have  been  sufficiently  shel- 
tered to  encourage  the  growth  of  kelp  and  ,sea  lettuce  and 
other  sea  weeds  to  which  many  of  the  smaller  univalves  and 
bivalves  characteristically  attach  themselves.  The  Calvert 
of  Maryland  is  unusually  varied  for  the  latitude.  It  is  quite 
possible  that  the  ancient  shore  line  in  that  area  was  fringed 
with  islands  and  sand  spits  similar  to  those  along  the  outer 
margin  of  Virginia  and  North  Carolina  today  and  that  dur- 
ing Calvert  times  the  spits  were  now  washed  away,  admitting 
the  off-shore  fauna,  and  now  built  up,  protecting  the  waters 
behind  them  and  allowing  a  warmer  water  element  to  creep 
in  and  establish  itself. 

There  is  no  evidence  of  any  marked  change  in  the  ecology 
in  passing  from  the  Calvert  to  the  St.  Mary's.  All  of  the 
recent  species  represented  in  the  Calvert  are  present  in  the 
St.  Mary's  but  the  number  is  almost  tripled.  The  northern 
element,  however,  is  slightly  less  prominent  and  the  southern 
element  a  little  more  so.  The  fauna  is  prolific  in  individuals 
but  not  greatly  diversified.  The  outstanding  differences  be- 
tween the  St.  Mary's  molluscs  of  Maryland  and  those  of 
Virginia  and  North  Carolina  are  mainly  those  of  latitude, 
although  the  presence  in  Maryland  of  a  considerable  number 
of  Surculas,  one  of  the  characteristically  deep-water  pleuroto- 
mids  suggests  deeper  water  in  that  area.  The  faunas  in  Vir- 
ginia and  North  Carolina  are  remarkably  uniform.  There 
are,  to  be  sure,  a  few  species  common  to  Maryland  and 
northern  Virginia  which  are  not  found  in  North  Carolina 
and  a  few  of  southern  affinities  which  are  restricted  to  North 
Carolina.  The  monotony  of  the  assemblage  indicates  a  long 


42  Environment  of  Tertiary  Marine  Faunas       [240 

stretch  of  open  shore  with  only  an  occasional  bight  from  the 
vicinity  of  the  present  York  River  in  Virginia  to  that  of 
the  Neuse  River  in  North  Carolina.  The  slope  of  the  conti- 
nental shelf  must  have  been  very  gentle,  not  more  than  3'  to 
the  mile,  since  there  is  no  perceptible  change  in  the  bathy- 
metric  character  of  the  fauna  between  the  extreme  eastern 
and  western  outcrops,  a  distance  of  60  or  70  miles.  There 
is  no  reason  to  believe  that  any  part  of  this  platform  was 
submerged  to  a  depth  of  more  than  30  or  40  fathoms.  The 
bottom  was  doubtless  soft  and,  for  the  most  part,  muddy 
since  the  mud-burrowers,  notably  Mulinia  are  exceedingly 
prolific  and  widely  distributed.  The  waters  must  have  been 
sufficiently  clear,  however,  and  the  bottom  sufficiently  shelly 
to  furnish  clutch  for  the  numerous  oyster  spat  and  to  permit 
them  to  mature.  Conditions  were  probably  not  very  favor- 
able to  algal  growth,  since  most  of  the  groups  which  charac- 
teristically attach  themselves  to  the  sea-weeds  of  various 
kinds  have  a  meagre  representation. 

The  elevation  along  the  Hatteras  axis  at  the  close  of  the 
St.  Mary's  was  apparently  great  enough  to  cut  off  the  York- 
town  basin  in  Virginia  from  the  Duplin  in  southern  North 
Carolina.  The  faunas  of  the  two  basins,  though  similar  in 
general  character,  differ  more  in  detail  than  one  would  expect 
in  two  shallow  water  faunas  only  a  couple  of  hundred  miles 
apart.  The  contemporaneity  of  the  Yorktown  and  Duplin 
faunas  was  suggested  by 'Dr.  Dall  more  than  fifteen  years  ago 
and  even  at  that  time  he  brought  forward  in  explanantion  of 
the  conspicuous  faunal  differences  the  potency  of  the  ocean 
currents,  a  factor  which  has  been  so  emphasized  of  late  in  the 
distributional  studies  upon  the  West  Coast.  The  Yorktown 
fauna  is  strikingly  like  that  listed  by  Bartsch  and  Henderson 
from  Chincoteague  Bay,  Accomac  County,  Virginia.  The 
greatest  break  in  the  East  Coast  life  from  the  late  Tertiary  on 
to  the  Recent  comes  at  Hatteras,  the  point  at  which  the  Gulf 
stream  leaves  the  inshore  and  swings  out  toward  the  open 
sea.  Many  of  the  sub-tropical  species  are  able  to  follow  along 
the  shore  as  far  as  it  is  protected  by  the  warm  current,  which 


241]  /.  A.  Gardner  43 

also  serves  as  an  effective  barrier  to  most  of  the  northern 
forms.  At  Chincoteague,  Bartsch  and  Henderson  found  that 
while  along  the  ocean  side  of  Chincoteague  Island  the 
fauna  was  consistently  northern  in  its  affinities,  in  the  pro- 
tected inner  bight  there  was  an  overlap  of  the  southern 
faunas.  Twenty-eight  of  the  70  species  which  they  have  listed 
are  present  in  the  Yorktown  fauna  and  the  number  of  com- 
mon forms  will  doubtless  be  greatly  increased  with  further 
investigations.  The  ensemble  of  the  fossil  and  Eecent  faunas 
is  conspicuously  similar  although  the  southern  element  is 
a  little  stronger  in  the  former.  However,  much  the  same 
conditions  of  sandy  shores  and  muddy  bogs  more  or  less 
choked  with  algal  growth  obtained  in  the  Yorktown  as  along 
the  Virginia  coast  today.  The  fauna,  like  those  that  precede 
and  those  that  follow  it,  is  characteristically  shallow  water 
and  it  is  doubtful  if  any  of  the  indigenous  species  lived  at 
a  depth  of  more  than  25  fathoms. 

The  Duplin  fauna  is  less  homogeneous.  Mingled  with  the 
large  pleurotomid  element  and  a  considerable  number  of 
volutoids,  one  of  the  most  uniformly  deep-water  families, 
are  nine  species  of  Ilyanassa,  a  group  that  is  known  to  occur 
only  along  inter-tidal  beaches.  The  sediments  of  the  Duplin 
are,  for  the  most  part,  coarse  sands.  It  seems  on  the  whole 
reasonable  to  suppose  that  the  native  Duplin  fauna  lived  near 
the  mouth  of  some  rather  large  estuary  and  that  the  streams 
entering  the  bay  brought  down  in  considerable  numbers  the 
beach-dwellers  from  farther  up  shore,  while  strong  currents 
from  the  south  sweeping  along  the  mouth  of  the  estuary 
contributed  not  only  a  southern  element  of  living  forms  but 
also  a  large  number  of  dead  shells  referrable  to  extra-limital 
species.  One  hundred  and  thirteen  Duplin  species  are  either 
identical  with  the  Recent  forms  or  so  closely  allied  that  they 
have  been  confused  in  the  synonymies.  Of  this  number  97, 
approximately  85%,  occur  between  Hatteras  and  Florida.  Of 
the  remaining  18  only  a  single  species,  the  rather  uncommon 
Polynices  heros,  does  not  range  as  far  south  as  Hatteras. 
Most  of  the  characteristic  Florida  elements,  however,  are 


4:4  Pelecypods  of  the  Boiuden  Fauna  [212 

absent,  so  that  it  seems  probable  that  Duplin  temperature 
conditions  are  more  nearly  duplicated  between  Cape  Fear 
and  Charleston,  South  Carolina,  than  along  any  other  sec- 
tion of  the  Coast. 

In  the  succeeding  Waccamaw  the  conditions  of  the  Duplin 
were  some  of  them  intensified  but  not  materially  changed. 
The  fauna  is,  on  the  whole,  more  consistent,  for  both  the 
brackish  and  the  deep  water  elements  are  rather  less  pro- 
nounced. There  were,  judging  by  the  abundance  of  such 
forms  as  the.  Olivas  and  Olivellas,  extensive  sand  flats  covered 
by  from  2  to  10  fathoms  of  water,  while  the  wealth  of 
Bittiums  and  small  Cerites  and  other  groups  of  similar  habits 
demands  conditions  favorable  for  extensive  algal  growth. 
There  is  a  curious  similarity  in  the  general  make-up  of  the 
Waccamaw  and  Yorktown  faunas,  due,  doubtless  to  the 
similarity  in  ecology.  The  Waccamaw  waters,  however,  were 
decidedly  warmer  than  those  of  the  Yorktown,  in  fact  they 
were  in  all  probability  warmer  than  at  any  other  period  during 
the  middle  or  late  Tertiaries  or  than  those  off  North  Carolina 
today.  The  evolution  toward  the  Recent  Cape  Fear  fauna 
has  been  marked  less  by  the  introduction  of  a  northern 
element  than  by  the  restriction  of  the  more  sensitive  southern 
forms  to  the  Floridian  province. 


THE   PELECYPODS   OF   THE   BOWDEN   FAUNA 

By  WENDELL  P.  WOODRING 


1.     INTRODUCTION 

The  marls  exposed  along  the  coast  between  Morant  Bay  and 
Port  Morant,  near  Bowden,  almost  at  the  southeastern  ex- 
tremity of  the  island  of  Jamaica,  have  long  been  known  to 
contain  a  prolific  and  splendidly  preserved  molluscan  fauna. 
In  1862  Mr.  Lucas  Barrett,  the  Director  of  the  Jamaican 
Survey,  deposited  in  the  British  Museum  a  collection  ap- 
parently from  this  locality.  A  year  later  Mr.  Carrick  T. 


243]  W.  P.   Woodring  45 

Moore 2  submitted  a  brief  report  on  the  mollusca.  The  first 
systematic  account  of  the  fauna  was  published  in  1866  by 
the  late  Mr.  E.  J.  Lechmere  Guppy,3  who  later  made  several 
additional  contributions.4  Mr.  Eobert  Etheridge  5  in  an  ap- 
pendix to  the  report  of  the  Jamaican  Survey,  published  in 
1869,,  discussed  the  general  aspect  of  the  fauna.  In  1896 
Guppy  and  Ball6  issued  descriptions  of  a  number  of  new 
species.  The  report  of  Mr.  Eobert  T.  Hill 7  on  his  recon- 
naissance of  Jamaica  contained  a  brief  notice  of  the  mollus- 
can  elements  of  the  fauna.  In  the  Wagner  Institute  Papers 
Dr.  Dall 8  described  many  new  species  and  noted  the  occur- 
ence  of  previously  described  forms;  in  addition,  the  last 
fascicle  contained  a  discussion  of  the  correlation  of  the  fauna 
and  a  check-list.9 

2.     BIOLOGICAL  CHARACTER  OF  THE  FAUNA 

The  present  study  has  resulted  in  the  recognition  of  be- 
tween 190  and  200  species  of  pelecypods,  of  which  almost 
half  are  new.  These  are  segregated  into  64  genera  and  40 
families.  The  superspecific  groups  and  the  number  of 
species  in  each  group  are  given  in  the  following  list: 


2  Moore,  C.  T.,  Quart.  Jour.  Geol.  800.,  London,  vol.  19,  pp.  510-513, 
1863. 

3  Guppy,  R.  J.  L.,  Quart.  Jour.  Geol.  Soc.,  London,  vol.  22,  pp.  281- 
295,  1866. 

4  Guppy,  R.  J.  L.,  Geol.  Mag.,  decade  v,  vol.  4,  pp.  496-501,  1867: 
idem,  decade  2,  vol.  1,  pp.  404-411;  436-446,  1874;  idem,  vol.  2,  pp. 
41-42,  1875;  Proc.  Assoc.  Trinidad. 

5  Etheridge,  R.,  Reports  on  the  Geology  of  Jamaica,  Part  2,  West 
Indian  Survey,  Mem.  Geol.  Survey  Great  Britain,  ap.  5,  pp.  319-329, 
1869. 

6  Guppy,  R.  J.  L.,  and  Dall,  W.  H.,  Proc.  U.  S.  Nat.  Mus.,  vol.  19, 
no.   1110,  pp.  303-331,   1896. 

7  Hill,  R.  T.,  Bull.  Mus.  Compt.  ZooL,  Harvard,  vol.  34   (geol.  ser. 
4),  pp.  145-152,  1899. 

8  Dall,  W.  H.,  Trans.  Wagner  Free  Inst.  fifci.,  Philadelphia,  vol.  3, 
pts.  1-6,  1890-1903. 

9  Idem.,  pt.  6,  pp.  1580-1588,  1903. 


4:6  Pelecypods  of  the  Bowden  Fauna  [24-i 

Nucula  2  pp. 

Leda  7  spp. 

Yoldia  1  spp. 

Tindaria   1   spp. 

Limopsis  2   spp. 

Area  (Area  s.  s.)  4  spp. 

Barbatta   (Acar)   2  spp. 

(Calloarca)  4  spp. 
(new  section)   3  spp. 
(Fossularca)   2  spp. 
Scapharca  (Scapharca  s.  s.)  9  spp. 
(Argina)    1  sp. 
(Cunearca)    1  sp. 
(Bathyarca)   1  sp. 
(Anadara)    1  sp. 
Glycymeris  3  spp. 
Pinna  1  sp. 
Atrina  1  sp. 
Melina  1  sp. 
Pteria  1  sp. 
Ostrea  3  spp. 
Pecten 

Pecten  (Pecten  s.  s.)   1  sp. 

(Euvola)   2  spp. 
Chlamys  (Chlamys  s.  s.)  4  spp. 
(Aequipecten)  5  spp. 

Pseudamusium  ( Pseudamusium  s.  s.)  1  sp. 
Amusium  (Amusium  s.  s.)   1  sp. 
(Propeamusium)    1   sp. 
Spondylus  3  spp. 
Plica  tula  1  sp. 
Lima  (Lima  s.  s.)  1  sp. 

Lima   (Mantellum)    1  sp. 
Limaea  1  sp. 
Placuanomia   1   sp 
Anomia  2  spp. 

Modiolus   (Brachydontes)    1  sp. 
Dreissena  1  sp. 
Julia  1  sp. 
Verticordia  (Trigonulina)  1  sp. 

(Haliris)    1  sp. 
Poromya  1  sp. 
Cuspidaria  (Cardiomya)  1  sp. 
(Bowdenia)  1  sp. 
Crassatellites  (Crassatellites  s.  s.)  2  spp. 

(Crassinella)  3  spp. 
Venericardia  (Venericardia  s.  s.)  1  sp. 

(Pteromeris)  1  sp. 
Chama  2  spp. 
Echinochama  1  sp. 
Codakia  (Codakia  s.  s.)   2  spp. 

(Jagonia)  3  spp. 
Myrtaea   (Myrtsea  s.  s.)  s  spp. 

(Eulopia)  3  spp. 

Phacoides  (Phacoides  s.  s.)   1  spp. 
Here  (Here  s.  s.)  4  spp. 
(Pleurolucina)  1  sp. 
(Cavilucina)  1  sp. 


245]  W.  P.  Woodring  47 

Pseudomiltha  1  sp. 

Callucina  3  spp. 

Parvilucina  (Parvilucina  s.  s.)  3  spp. 

(Bellucina)  2  spp. 
Divaricella  2  spp. 

Diplodonta  (Diplodonta  s.  s.)  2  spp. 
(Pelaniella)  1  sp. 
(Phlyctiderma)   1  sp. 
Erycina  2  spp. 

Anisodonta  (Basterotia)  1  sp. 
Montacuta?  1  sp. 
Cardium  (Cardium  s.  s.)  1  sp. 

Trachycardium  4  spp. 

Fragum  (Fragum  s.  s.)  2  spp. 

(Trigoniocardia)  3  spp. 

Laevicardium  1  sp. 
Protocardia  2  spp. 
Transennella  2 'spp. 
Tivela  1  sp. 

Gafrarium  (Gouldia)  1  sp. 
Pitaria   (Hyphantosoma)    1  sp. 
(Lamelliconcha)    1   sp. 
Antigona  (Ventricola)  1  sp. 
Cyclinella  1  sp. 
Chione  (Chione  s.  s.)  3  spp. 

Chione  (Lirophora)  1  sp. 
Parastarte  1  sp. 
Cooperella  (new  section)  1  sp. 
Tellina 

Arcopagia  (Merisca)  4  spp. 

(Phyllodina)   2  spp. 
(Eurytellina)  1  sp. 

Moerella  2  spp. 

Angulus  (Angulus  s.  s.)  5  spp. 

(Scissula)  1  sp. 
Strigilla  1  sp. 
Macoma 

Psammacoma  (Psammacoma  s.  s.)  2  spp. 

Cymatoica  1  sp. 
Semele  (Semele  s.  s.)  1  sp. 
Abra  2  spp. 
Donax  2  spp. 
Psammosolen  1  sp. 
Spisula  1  sp. 
Ervilia  1  sp. 
Corbula  (Aloidis)  1  sp. 

(Cuneocorbula)  1  sp. 
(Bothrocorbula)  1  sp. 
Gastrochaena  1  sp. 
Martesia?  1  sp. 
Xylophaga?  1  sp. 
Teredina  1  sp. 
Teredo  1  sp.10 


10 


An  additional  form  is  considered  the  type  of  a  new  genus  of 
doubtful  affinities  placed  provisionally  among  the  Isocardiacea,  prob- 
ably near  the  Vesicomyacidas. 


48  Pelecypods  of  the  Bowden  Fauna  [246 

The  Prionodesmacea  play  an  important  role  in  the  constitu- 
tion, being  represented  by  79  species,  or  more  than  40  per 
cent  of  the  fauna.  The  larger  part  of  this  number  is  contri- 
buted by -the  taxodonts,  which  include  44  species.  The  most 
abundant  taxodont  is  the  genus  Area,  which  has  28  species 
distributed  among  10  sections.  The  Scapharcas  are  the  most 
prolific,  both  individually  and  specifically.  The  section 
Cunearca,  which  usually  occupies  a  position  of  importance  in 
the  mid-Tertiary  faunas  of  the  Antillean  region  and  its  peri- 
meters, is  represented  by  a  single  small  form  and  the  sub- 
genus  Noetia  is  entirely  absent.  Three  species  of  Barbatia 
are  grouped  in  a  new  section  that  bears  a  relation  to  Barbatia 
s.  s.  similar  to  the  relation  between  Argina  and  Scapharca 
s.  s.  Another  Barbatia  of  unusual  type  has  been  provisionally 
referred  to  Fossularca,  although  it  probably  represents  a  new 
section.  A  minute  Bathyarca  is  abundant  in  one  of  the  col- 
lections, but  is  rather  rare  in  the  other  minute  collections 
available. 

Among  the  prionodonts  the  Pectens  are  subordinate  only 
to  the  Areas.  They  contribute  15  species  representing  seven 
sections  among  which  are  included  virtually  all  the  groups  of 
a  typical  tropical  fauna.  The  Aequipectens  are  the  most 
abundant  and  include  several  species  that  are  widely  distri- 
buted in  the  Tertiary  deposits  of  the  Antillean  region.  With 
regard  to  specific  diversification  Chlamys  s.  s.  is  comparable 
to  Aequipecten,  but  only  one  of  the  species  is  abundant.  The 
valves  of  a  small  delicate  Pseudamusium  s.  s.  are  numerous 
and  the  section  Propeamusium  is  represented  by  a  single 
valve. 

The  oysters  form  a  puzzling  assemblage.  In  all  the  collec- 
tions the  number  of  individuals  is  small  and  large  forms  are 
notably  absent.  The  small  size  is  probably  not  without  sig- 
nificance when  it  is  considered  that  one  of  the  Bowden  species 
reaches  an  imposing  size  in  the  Alum  Bluff  faunas  and  especi- 
ally in  the  Santo  Domingan  fauna.  A  similar  relation 
obtains  for  an  unusually  large  and  ponderous  Santo  Do- 
mingan Spondylus.  If  the  current  synonymy  for  Ostrea 


247]  W.  P.  Woodring  49 

megodon  Hanley  is  accepted,  this  species  furnishes  an  example 
of  a  former  distribution  on  both  sides  of  the  Isthmus  of 
Panama  and  a  present  restriction  to  the  Pacific  side.  Another 
oyster  probably  is  identical  with  the  Eecent  mangrove- 
oyster,  0.  folium  Linnaeus.  Although  the  species  may  not  be 
genetically  valid,  it  may  be  assumed  that  the  Bowden  form 
had  the  peculiar  habits  of  the  oyster  that  is  frequently  found 
in  mangrove  swamps  in  the  Antillean  region. 

The  family  Limidae  includes,  in  addition  to  the  common 
Lima,  the  rare  Limcea.  Likewise  among  the  Anomindae  is 
found  the  uncommon  Placunanomia,  as  well  as  the  ubiquitous 
Anomia.  The  brackish-water  Dreissena  is  not  frequently 
encountered  among  American  Tertiary  faunas.  Of  greater 
interest  is  the  presence  of  the  extremely  rare  Julia,  a  genus 
that  at  the  present  time  is  confined  to  the  Indo-Pacific  region 
and  is  represented  by  only  a  few  fossil  species — one  from  the 
Oligocene  of  Florida  and  two  from  the  Miocene  of  south- 
western France. 

A  minor  element  in  the  fauna  is  furnished  by  the  Anomalo- 
desmacea.  The  five  species  are  confined  to  the  superfamily 
Poromyacea  and  include  small  forms  under  the  families  Ver- 
ticordiidae,  Poromyacidae  and  Cuspidariidae.  One  of  the 
Cuspidarias  is  the  type  of  the  subgenus  Bowdenia  Ball. 

.The  relative  importance  of  the  Teleodesmacea  is  dimin- 
ished by  the  unusually  large  number  of  prionodonts,  although 
naturally  the  teleodonts  include  the  bulk  of  the  fauna. 
Among  the  Astartacea  members  of  the  family  Astartidae  are 
conspicuously  absent,  but  the  Crassatellitidae  are  represented 
by  five  species  of  Crassatellites,  of  which  the  most  important 
and  the  most  abundant  belong  to  the  subgenus  Crassinella. 
ISTo  Carditas  are  present,  but  the  genus  Venericardia  includes 
a  prolific  Venericardia  s.  s.  and  also  a  small  curious  form 
that  has  been  referred  to  the  subgenus  Pteromeris,  although 
it  is  hardly  typical  of  that  group. 

The  superfamily  Lucinacea  is  the  most  diversified  of  the 
larger  groups.  Although  only  five  genera  are  included,  they 
are  represented  by  32  species.  The  genus  Phacoides  alone 


50  Pelecypods  of  the  Bowden  Fauna  [248 

furnishes  half  of  the  species  distributed  among  eight  sections. 
Two  phacoidean  elements,  Lucinisca  and  Miltha,  as  well  as 
the  genus  Lucina,  are  absent.  The  Codakias  and  Myrtaeas 
are  abundant  and  well-developed.  The  Divaricellas  are  indi- 
vidually numerous,  whereas  the  Diplodontas  are,  as  usual, 
represented  by  a  small  number  of  individuals. 

In  contrast  to  the  richness  of  the  lucinoids  is  the  meager 
representation  of  the  Leptonacea.  The  entire  superfamily 
includes  but  four  species  segregated  into  three  genera  and  as 
many  families.  Furthermore,  the  four  species  are  represented 
by  only  six  valves,  two  of  which  belong  to  the  rarely  encoun- 
tered subgenus  Basterotia  of  the  genus  Anisodonta. 

Among  the  larger  groups  is  the  genus  Cardium,  represented 
by  seven  sections  and  eleven  species.  The  sections  are  such 
as  are  found  in  any  tropical  or  sub-tropical  mid-Tertiary 
American  fauna,  but  Cerastoderma  and  Papyridea  are  not 
included.  The  Trigoniocardias,  which  are  peculiar  to  the 
mid- American  region,  are  a  conspicuous  element;  indeed,  a 
species  of  this  section  is  the  most  abundant  bivalve  in  the 
fauna. 

The  eight  veneroid  genera  are  divided  among  the  sub- 
families Meretricinae,  Venerinae  and  Geminae.  Chione  is 
the  most  abundant  with  regard  to  both  the  number  of  species 
and  individuals.  Parastarte,  represented  by  a  single  valve, 
has  heretofore  not  been  reported  outside  of  the  Floridian 
region  either  recent  or  fossil.  The  genus  Tivela  is  not  in- 
cluded in  any  of  the  Tertiary  faunas  of  the  North  American 
mainland.  An  interesting  form  comparable  to  Cooperella  in 
dentition  is  placed  in  a  new  section  of  that  genus.  Only  two 
species  of  Cooperella  are  known,  a  Recent  species  from  the 
west  coast  of  North  America  and  another  from  the  late  Mio- 
cene of  the  Atlantic  Coast. 

The  genus  Tellina  includes  15  species,  distributed  among 
6  sections.  Angulus  has  the  largest  number  of  species,  but 
the  most  abundant  forms  are  found  under  Merisca  and  Moe- 
rella.  Among  the  Macomas  is  a  typical  Cymatoica.  The 
remaining  Teleodesmacea  are  scattered  among  several  groups. 


249]  W.  P.  Woodring  51 

A  single  fragmentary  valve  of  an  indeterminable  Spisula  is 
the  sole  representative  of  the  Mactridae.  Two  of  the  three 
species  of  Corbula,  the  only  non-boring  Myacea,  are  exceed- 
ingly abundant.  The  unusually  favorable  conditions  of  pre- 
servation are  indicated  by  the  presence  of  several  fragile 
boring  Adesmacea. 

3.     PHYSICAL  CONDITIONS 

The  student  of  recent  marine  faunas  would  consider  with 
undisguised  suspicion  an  attempt  to  reconstruct  environ- 
mental conditions  on  the  basis  of  the  testimony  furnished  by 
a  single  element  in  a  fauna.  Despite  the  lack  of  an  intensive 
census  of  a  restricted  shallow-water  West  Indian  area,  which 
would  be  of  inestimable  value  in  projecting  backward  the  fac- 
tors that  determined  the  assemblage  of  an  Antillean  Tertiary 
fauna,  the  ensemble  of  Bowden  pelecypods  is  such  as  to  per- 
mit the  offering  of  certain  considerations,  some  of  which  are 
more  or  less  obvious  and  even  trite. 

Though  it  is  a  mere  platitude  to  state  that  the  fauna  is 
tropical,  yet  this  facies  is  emphasized  in  a  striking  manner 
by  the  development  of  certain  groups  and  the  absence  of 
others  that  are  prominent  in  the  Tertiary  faunas  of  the  south- 
ern Atlantic  Coast.  The  most  prolific  genera — Area,  Pecten, 
Phacoides,  Cardium,  Tellina — are  characteristically  tropical 
or  are  represented  only  by  sections  or  species  that  are  con- 
fined to  low  latitudes  or  there  reach  their  maximum  develop- 
ment. According  to  the  latest  faunal  lists  only  two  of  the  18 
species  that  persist  to  the  Recent  at  present  range  north  of 
Cape  Hatteras — the  ubiquitous  Anomia  simplex  d'Orbigny 
and  Divaricella  quadrisulcata  (d'Orbigny).  Eight  are  re- 
corded from  Hatteras  southward  to  the  West  Indies  or  Brazil ; 
seven  are  confined  to  the  area  south  of  Florida  and  one  species 
is  restricted  to  the  tropical  portion  of  the  West  Coast.  Vir- 
tually the  same  proportions  obtain  for  a  large  number  of 
Recent  species  that  closely  resemble  Bowden  forms. 

The  Areas  reach  their  greatest  importance  in  the  warmer 


52  Pelecypods  of  the  Bowden  Fauna  [250 

seas.  The  Bowden  species  are  such  as  would  be  expected  in 
tropical  waters ;  indeed  a  number  of  them  are  encountered  in 
the  present  West  Indian  fauna.  The  genus  Pecten  is  usually  a 
conspicuous  element  in  the  Tertiary  and  Eecent  faunas  of  all 
latitudes,  but  the  large  species  that  are  characteristic  of  higher 
latitudes,  are  absent.  Spondylus  is  confined  to  tropical  or 
sub-tropic  regions  in  the  Eecent  seas.  In  the  middle  and  late 
Tertiary  faunas  of  the  United  States  the  genus  is  restricted  to 
rare  occurrences  in  the  Meridian  region.  Perhaps  the  most 
obvious  indication  of  the  temperature  of  the  waters  is  fur- 
nished by  the  superfamily  Astartacea,  which  is  represented 
only  by  several  Crassatellites.  Even  the  warm-water  Caloosa- 
hatchie  and  Waccamaw  faunas  include  one  or  two  Astartes, 
but  in  the  Bowden  assemblage  the  genus  is  entirely  absent. 
An  Echinochama,  a  genus  which  is  preeminently  Antillean, 
is  the  most  ponderous  bivalve  in  the  fauna.  The  entire  group 
of  lucinoids  is  quite  partial  to  tropical  waters,  although  a  few 
species,  especially  of  the  genus  Divaricella,  range  into  high 
latitudes.  By  far  the  greater  number  of  the  Cardiums  are  of 
the  ornate  type  that  indicates  a  warm-water  habitat.  More- 
over, the  smooth  or  relatively  simple  forms  are  identical  with, 
or  closely  related  to,  Eecent  species  that  do  not  occur  north  of 
Florida.  Although  the  distribution  of  the  genus  Tellina  is 
almost  world-wide  the  group  is  predominantly  tropical. 

In  attempting  to  determine  the  depth  of  the  water  from  a 
consideration  of  the  bathymetric  range  of  identical  or  closely 
related  Eecent  species  a  rigid  adherence  to  the  evidence  fur- 
nished by  dredging  records  would  often  lead  to  absurd  con- 
clusions. An  example  is  furnished  by  the  genus  Limopsis,  of 
which  two  species  are  present.  According  to  available  data 
the  group  as  a  whole  is  characteristic  of  deeper  water,  yet 
several  species  occur  in  Eocene  beds  of  the  Gulf  Coast  that 
undoubtedly  were  deposited  in  very  shallow  water. 

The  fauna  is  essentially  a  shallow- water  fauna.  All  of  the 
Eecent  species  occur  in  water  of  shallow  depth  and  many  have 
been  recorded  from  the  intertidal  zone,  but  the  range  of  sev- 


251]  W.  P.  Wo'odring  53 

eral  is  extended  into  considerably  deeper  water.  The  presence 
of  apparently  deeper  water  elements,  such  as  Tindaria  and 
Bathyarca,  may  be  the  result  of  the  action  of  currents  or  other 
extra-limital  factors.  Since  but  a  single  valve  of  Tindaria  is 
present  it  is  doubtful  whether  the  form  was  indigenous.  It 
may  be  suggested  that  the  depth  did  not  exceed  30  or  40 
fathoms  and  it  is  highly  probable  that  the  bulk  of  the  fauna 
lived  in  water  that  was  considerably  shallower. 

The  waters  were  clear  and  the  bottoms  free  from  mud.  By 
far  the  larger  number  of  the  Bowden  pelecypods  are  partial 
to  bottoms  of  sand  or  fine  gravel;  even  the  burro wers  are 
usually  found  on  sandy  bottoms.  The  absence  of  Mulinia 
and  related  forms  that  prefer  a  muddy  bottom  is  not  without 
significance.  The  meager  representation  or  absence  of  the 
Leptonacea  and  other  small  forms  that  usually  frequent 
muddy  bottoms  in  sheltered  near-shore  positions  or  are 
attached  to  algae  indicates  an  open  coast  and  rather  strong 
current  action.  Estuaries  interrupted  the  coast  line  and  led 
back  to  the  streams  that  supplied  the  relatively  coarse  volcanic 
debris  which  constituted  the  bulk  of  the  sediments.  From  the 
estuaries  valves  of  Dreissena  and  the  mangrove-oyster  were 
carried  down  to  the  coast  and  mixed  with  the  indigenous  beach 
and  off-shore  dwellers. 

4.    EELATIONS  TO  THE  FAUNAS  OF  THE  NORTH  AMERICAN 
MAINLAND 

The  possibility  of  comparing  an  Antillean  Tertiary  fauna 
with  those  of  the  Floridian  Peninsula  is  enhanced  by  the 
proximity  of  the  areas  and  by  the  succession  of  tropical  or 
sub-tropical  faunas  of  the  mainland.  Dall11  has  correlated 
the  Bowden  horizon  with  the  top  of  the  Alum  Bluff  formation 
which  includes  the  Chipola,  Oak  Grove  and  Shoal  Eiver  mem- 
bers in  ascending  order.  According  to  Dall 12  the  Chipola 


"Ball,  W.  H.,  Trans.  Wagner  Free  Inst.  Sci.,  Philadelphia,  vol.  3, 
pt.  6,  pp.  1560,  1582,  1903;  Bull.  U.  8.  Nat.  Mus.  90,  p.  8,  1916. 
12  Dall,  W.  H.,  loc.  tit.,  p.  1574,  1903. 


54  Pelecypods  of  the  Bowden  Fauna  [252 

fauna  indicates  distinctly  sub-tropical  conditions.  Berry 13 
has  shown  that  the  Alum  Bluff  flora  is  sub-tropical  or  very 
warm  temperate  and  according  to  Dall 14  the  Oak  Grove  fauna 
indicates  a  slight  lowering  of  temperature.  Above  the  Alum 
Bluff  formation  is  a  sharp  break  that  has  been  seized  upon  as 
a  convenient  location  for  the  division  between  the  Oliocene 
and  Miocene.  Though  the  succeeding  Miocene  faunas  of 
Florida  are  imperfectly  known  they  unquestionably  indicate 
a  more  temperate  f acies  15  and  occupy  a  position  near  the 
middle  of  the  Miocene  series  of  Virginia  and  the  Carolinas. 
The  Pliocene  Caloosahatchie  formation  of  Florida  has  yielded 
a  rich  sub-tropical  fauna. 

The  profound  hiatus  in  the  Floridian  succession  is  par- 
tially bridged  by  the  Miocene  deposits  of  Virginia  and  the 
Carolinas.  According  to  Berry 16  the  Calvert  formation, 
which  is  the  oldest,  is  middle  Miocene,  probably  Tortonian. 
The  only  faunas  of  this  region  that  present  a  warm-water 
f  acies  are  those  of  the  late  Miocene  Duplin  and  the  succeeding 
Pliocene  Waccamaw,  both  of  which  are  warm  temperate  rather 
than  sub-tropical.  It  is  apparent  that  an  attempt  to  compare 
a  mid-Tertiary  Antillean  fauna  with  the  faunas  of  Florida  is 
seriously  hampered  by  the  absence  of  any  tropical  or  sub- 
tropical Miocene  faunas  on  the  mainland.  Furthermore,  in 
order  to  make  comparisons  with  any  warm-water  Miocene 
fauna  of  the  Atlantic  Coast  it  is  necessary  to  resort  to  the 
geographically  distant  warm  temperate  Duplin  fauna.  In 
Florida  the  only  post- Alum  Bluff  marine  assemblage  that 
flourished  under  conditions  in  any  manner  comparable  to 
those  of  an  Antillean  fauna  is  the  sub-tropical  Pliocene 
Caloosahatchie  fauna,  which  is  appreciably  younger  than  the 
slightly  more  temperate  Waccamaw  fauna. 


"Berry,  E.  W.,  U.  S.  Geol.  Survey  Prof.,  Paper  98-E,  pp.  43-44, 
1916. 

"Ball,  W.  H.,  loo.  tit.,  pp.  1549,  1581,  1588-1589,   1903. 
15  Dall,  W.  H.,  loc.  tit.,  pp.  1549,  1589,  1594,  1903. 
"Berry,  E.  W.,  U.  S.  Geol.  Survey  Prof.,  Paper  98-F,  p.  66,  1916. 


253]  W.  P.  Woodring  55 

The  Chipola  marl  among  the  Florida  horizons  has  the 
largest  number  of  species  in  common  with  the  Bowden.  The 
actual  number  is  of  little  significance  since  the  Caloosahatchie 
has  almost  the  same  number.  It  is  significant,  however,  that 
the  Chipolan  elements  are  completely  overshadowed  by  the 
closer  affinities  of  a  large  number  of  groups  with  Duplin  and 
even  "Waccamaw  and  Caloosahatchie  forms.  Difficulties  are 
encountered  in  interpreting  these  modern  elements  in  terms 
of  age  relations  to  the  faunas  of  the  mainland,  since  obviously 
considerations  of  facies  and  geographical  proximity  are 
involved.  A  larger  number  of  Bowden  species  are  found  in 
the  present  West  Indian  waters  than  in  any  of  the  Florida 
Tertiary  faunas  and  more  forms  are  common  to  the  Caloosa- 
hatchie than  to  the  Oak  Grove,  Duplin  or  Waccamaw. 

The  taxodonts  supply  one-third  of  the  total  number  of 
Recent  species  and  all  of  these  are  found  among  the  Arcidae, 
hence  that  family,  and  especially  the  sub-family  Arcinae,  has 
a  modern  aspect.  Five  Eecent  Areas  are  included  in  the  list 
and  several  others  are  very  closely  allied  to  Eecent  forms. 
Four  of  the  Areas  that  persist  to  the  Recent  are  found  in  the 
Chipola  fauna  and  three  in  the  older  Tampa,  so  that  the 
actual  number  is  of  little  weight.  But  a  modern  element  is 
furnished  by  the  introduction  of  the  section  Bathyarca.  Two 
of  the  three  oysters  are  believed  to  be  identical  with  Recent 
species.  Among  the  Pectens  are  several  elements  that  are  not 
encountered  among  the  Oliocene  faunas  of  Florida;  these 
include  an  Euvola  of  modern  aspect,  several  Acquipectens  that 
are  most  closely  related  to  Pliocene  or  Recent  forms  and  a 
Propeamusium  of  decidedly  modern  type.  Among  the  remain- 
ing Prionodesmacea  the  genera  Limcea  and  Placuanomm  are 
unrepresented  in  the  Oligocene  of  the  Florida  section.  • 

A  Crassinella  strongly  suggests  a  Duplin  and  Waccamaw 
species.  Aside  from  a  Recent  Chama,  the  presence  of  the 
genus  EcJiinocJiama  lends  to  the  Chamidae  a  modern  appear- 
ance. The  Lucinacea  as  a  whole  present  a  modern  aspect. 
In  addition  to  several  species  that  are  more  closely  related  to 


56  Pelecypods  of  the  Bowden  Fauna  [254 

Duplin  or  later  forms,,  this  relation  is  emphasized  by  the 
initial  appearance  of  the  section  Pleurolucina  of  the  genus 
Phacoides.  Although  the  section  Eulopia  of  Myrtaea  has 
been  reported  from  the  Tampa  fauna,  it  reaches  its  earliest 
development  of  any  importance  in  the  Bowden  fauna  and  is 
not  present  in  any  of  the  post-Tampa  Florida  deposits.  A 
peculiar  Hare  represents  a  type  that  has  not  been  recognized 
except  in  the  Eecent  seas  and  typical  Bellucinas  have  not  been 
reported  from  horizons  lower  than  the  Duplin.  The  super- 
family  under  discussion  includes  a  Eecent  Divaricella  and  also 
a  Recent  Diplodonta,  which  is  unknown  from  any  intervening 
horizon.  Two  Eecent  Cardiums,  a  Fragum  and  a  Laevi- 
cardium,  are  confined  to  Miocene  and  later  horizons  on  the 
mainland,,  and  Trachycardium  includes  a  type  unknown  from 
beds  earlier  than  Pliocene.  The  Yeneridae  supply  a  quota  of 
later  Tertiary  elements.  The  Bowden  Tivela  is  the  only  rep- 
resentative of  the  genus  recorded  from  American  Tertiary 
deposits  and  a  Recent  species  of  Gafrarium  (Gouldia)}ias  not 
been  recognized  at  any  other  Tertiary  horizon.  The  single 
Cyclinella  is  very  close  to  a  Recent  species  and  the  most  abund- 
ant Chione  s.  s.  is  allied  to  a  Duplin  form.  The  genus  Paras- 
tarte,  unrecorded  from  a  pre-Miocene  horizon,  is  represented 
by  a  species  scarcely  distinguishable  from  the  Miocene  to 
Recent  type  of  the  genus.  Among  the  Tellinacea  are  to  be 
noted  a  Recent  Strigilla,  a  Semele  that  is  surprisingly  close  to 
a  Pliocene  and  Recent  form  and  the  initial  appearance  of  the 
subgenus  Cymatoica  of  the  genus  Macoma. 

Though  many  of  the  post-Chipolan  elements  are  found 
among  the  characteristically  tropical  groups,  yet  the  introduc- 
tion of  super-specific  groups,  some  of  which  are  not  exclu- 
sively tropical,  can  hardly  be  disregarded.  The  Bowden  pele- 
cypods  are  distinctly  younger  than  those  of  the  Alum  Bluff 
faunas,  as  those  faunas  are  now  known.  It  may  be  suggested 
that  the  Bowden  fauna  is  Burdigalian,  that  is,  Lower  Miocene 
in  the  sense  of  most  American  stratigraphers. 


255]  F.  Reeves  57 

ORIGIN  OF  THE  NATURAL  BRINES  OF  OIL  FIELDS 

By  FRANK  BEEVES 

The  origin  of  the  concentrated  brines  so  universally  found 
in  oil-bearing  strata  and  other  porous,  unmetamorphosed 
rocks  lying  at  depths  below  the  zone  of  active  circulating 
ground  water  has  never  been  definitely  established.  By  some 
these  waters  are  thought  to  be  of  meteoric  or  surface  origin, 
t.  e.,  they  are  rain  waters  which  have  in  passing  downward 
through  the  strata  dissolved  out  of  the  rock  material  the  salts 
which  they  now  hold  in  solution.  Others  consider  them  to  be 
the  sea  water  which  has  remained  in  the  pores  of  the  strata 
ever  since  their  deposition. 

A  study  of  the  occurrence  and  chemical  nature  of  the  brines 
found  in  the  oil  sands  of  southwestern  Pennsylvania  and  West 
Virginia  furnishes  data  which  indicate  that  the  waters  in  this 
area  are  connate  or  of  ocean  origin.  This  conclusion  is  based 
on  the  following  lines  of  evidence : 

(1)  The  distribution  of  the  water  suggests  that  it  is  not  of 
meteoric  origin. 

(2)  There  are  no  adequate  explanations  of  how  the  water 
of  deposition  has  been  removed  from  the  strata.  • 

(3)  The  association  of  the  dry  sands  and  "red  beds5'  of 
the  area  indicate  that  the  water  present  accumulated  with  the 
sediments  as  they  were  being  deposited. 

(4)  The  chemical  nature  of  the  brine  points  to  it  being  of 
connate  origin. 

THE  DISTRIBUTION"  OF  WATER 

In  order  to  consider  this  phase  of  the  evidence  it  will  be 
necessary  to  describe  briefly  the  structural  and  stratigraphic 
features  of  the  area  under  discussion. 

Structure  of  the  Area. — The  brines  occur  in  the  Car- 
boniferous and  Devonian  strata  of  the  Appalachian  coal  basin. 


58  Natural  Brines  of  Oil  Fields  [256 

This  is  a  shallow  geosyncline  in  which  the  surface  rocks  are 
chiefly  of  Pennsylvania!!  age  except  where  in  the  center  of  the 
basin  there  are  from  800  to  1300  feet  of  Permian  strata  over- 
lying the  Pennsylvanian.  In  this  area  the  Mississippian  and 
Devonian  rocks  underly  the  surface  at  from  1600  to  2000 
feet  and  2200  to  3000  feet,  respectively.  Around  the  rim  of 
the  basin  these  strata  outcrop.  On  the  east  they  reach  the 
surface  along  the  Alleghany  front  and  on  the  west  in  central 
Ohio.  The  distance  across  the  center  of  the  basin  from 
outcrop  to  outcrop  of  the  Devonian  strata  is  about  180 
miles.  The  difference  in  elevation  between  the  highest  and 
lowest  point  which  the  same  strata  attain  is  about  8000  feet. 
Thus  it  is  apparent  that  the  geosyncline  is  to  be  considered 
as  a  very  shallow  basin.  Across  the  basin  and  paralleling  the 
Appalachian  mountain  folds,  the  strata  are  folded  into  a 
series  of  minor  anticlines  and  synclines.  Towards  the  east- 
ern outcrop  these  flexures  become  more  and  more  pronounced. 
In  this  area  the  dip  along  the  flank  of  the  folds  is  about 
200  feet  to  the  mile,  while  in  the  central  part  of  the  basin  it 
seldom  exceeds  75  feet  to  the  mile.  Westward  the  folds  die 
out  almost  entirely  and  the  strata  rise  to  the  surface  in  central 
Ohio  at  the  rate  of  about  30  feet  to  the  mile.  The  strata 
under  consideration  therefore  are  comparatively  little  folded 
and  consequently  little  metamorphosed.  Faulting  is  also 
absent  except  for  a  minor  fault  of  a  few  miles  in  extent  in 
central  West  Virginia.  Southward  across  Kentucky  and 
Tennessee  the  basin  narrows  and  the  strata  are  folded  and 
faulted  to  a  greater  degree.  On  this  account  and  also  because 
of  the  lack  of  data  on  the  deep  underground  waters  of  the 
area  that  part  of  the  basin  is  not  included  in  this  discussion. 
The  northern  end  of  the  basin  is  also  not  considered  here  be- 
cause in  that  area  meteoric  water  has  entered,  through  old 
abandoned  oil  wells,  the  deeper  sands  and  destroyed  more  or 
less  the  original  water  content  of  these  strata. 

Stratigraphy  of  the  Area. — The  drill  has  penetrated  strata 
from  the  Permian  to  the  Lower  Devonian  in  the  search  of 
oil  in  the  central  part  of  the  basin.  The  Permian  and  Penn- 


257]  F.  Reeves  59 

sylvanian  are  the  surface  rocks.  They  comprise  a  series  of 
from  2000  to  2500  feet  of  alternating  thin-bedded  shales, 
sandstones,  limestones,  clays,  and  coals.  The  Mississippian 
underlies  the  Pennsylvanian  unconformably.  It  is  made  up 
of  about  800  feet  of  sandstone,  shales,  and  limestones  which 
vary  in  thickness  from  100  to  250  feet.  The  Catskill  forma- 
tion is  a  non-marine  facies  of  the  Upper  Devonian.  It  con- 
sists of  from  500  to  800  feet  of  thin-bedded  sandstones  and 
red  and  dark-colored  shales.  Below  the  Catskill  occur  about 
300,0  feet  of  compact  shales.  Underlying  these  are  the  Lower 
Devonian  limestones. 

Occurrence  of  the  Water. — Water  is  found  in  the  sandstone 
and  limestone  members  of  the  above  stratigraphic  series.  In 
these  it  occurs  in  porous  layers  in  which  also  occur  oil  and 
gas.  Usually  there  is  a  structural  arrangement  of  these 
materials.  Generally  the  water  occupies  the  synclines,  the 
gas  the  anticlines,  and  the  oil  intermediate  structural  posi- 
tions. This  distribution  is  modified  by  the  amount  of  water 
in  the  sands.  Where  they  are  saturated  the  oil  occupies  the 
anticlinal  areas.  In  the  Appalachian  oil  fields,  however,  the 
most  common  condition  encountered  is  where  there  is  but 
sufficient  water  to  fill  up  the  synclines.  The  oil,  under  such 
conditions,  occupies  a  belt  structurally  higher  and  the  gas  fills 
up  the  anticlinal  areas.  In  sands  that  contain  no  water  the 
oil  is  found  in  the  synclines. 

The  amount  of  water  in  a  sand  is  usually  thought  to  be  a 
function  of  its  depth.  In  general  it  may  be  stated  that  the 
Pennsylvanian  sands  are  saturated,  the  Mississippian  sands 
semisaturated,  and  the  Catskill  sands  dry.  This  would  appear 
to  support  the  idea  that  the  water  present  is  meteoric  in  ori- 
gin. On  examining  the  facts,  however,  this  assumption  does 
not  appear  to  be  justified  for  the  water  does  not  disappear 
with  depth.  Two  deep  wells  which  have  penetrated  the  Lower 
Devonian  strata  have  revealed  the  fact  that  below  the  dry 
Catskill  sands  are  prolific  water-bearing  strata  at  depths  from 
5000  to  6000  feet.  This  occurrence,  as  well  as  the  universal 
appearance  of  water  at  all  depths  in  other  oil  fields,  indicates 


60  Natural  Brines  of  Oil  Fields  [258 

that  depth  is  not  a  factor  in  the  disappearance  of  water.  This 
being  so,  then  the  usual  argument  that  the  water  present  has 
originated  from  descending  waters  loses  weight.  The  presence 
of  nonwater  bearing  sands  such  as  the  Catskill  occurring 
between  saturated  strata  goes  to  show  that  there  has  been  no 
downward  movement  of  meteoric  water  across  the  strata.  Thus, 
on  the  assumption  that  the  water  present  has  a  surface  origin 
it  must,  then,  have  reached  its  present  position  by  entering 
the  strata  at  their  outcrop.  This  undoubtedly  explains  the 
source  of  the  waters  occurring  in  strata  of  Pennsylvanian  age, 
for  these  are  saturated  up  to  their  outcrops  with  water  obvi- 
ously of  surface  origin.  But  the  saline  waters  in  the  Missis- 
sippi sandstones  are  not  present  towards  their  eastern  outcrop. 
The  synclines  along  the  eastern  flank  of  the  basin  contain 
no  water  and  these  would  have  to  be  filled  before  water  could 
reach  areas  in  the  sands  west  of  them.  It  is  impossible  that 
the  water  could  have  come  from  the  westward  for  some  of 
the  sands,  i.  e.,  the  Maxton  and  Hundred-foot  sands,  are  not 
continuous  to  the  western  outcrop  of  the  formations.  Thus 
with  these  facts  opposing  the  possibility  of  a  vertical  or  lateral 
movement  of  the  water  it  must  be  considered  to  be  of  connate 
origin. 

METHOD  OF  KEMOVAL  OF  WATER  OF  DEPOSITION 

The  processes  usually  suggested  by  which  the  sediments 
have  been  depleted  of  the  water  deposited  with  them  are 
hydration,  consolidation  of  the  sediments,  expansion  and 
evaporation  of  the  water  due  to  heat,  and  drainage  resulting 
from  elevation. 

A  brief  consideration  of  these  hypotheses  is  .sufficient  to 
prove  their  ineffectiveness. 

Hydration  cannot  have  been  a  factor  in  the  removal  of  the 
water  for  the  few  minerals  of  sedimentary  strata  capable  of 
combining  with  water  would  more  likely  be  hydrated  while 
they  were  accumulating  as  water-borne  sediments  than  while 
ihey  were  subjected  to  the  heat  and  pressure  incident  to  their 
condition  of  deeply  buried  strata. 


259]  F.  Reeves  61 

Consolidation  of  sediments  though  effective  in  lowering 
the  amount  of  pore  space  does  not  remove  the  water  from  the 
porous  area  that  remains  after  consolidation,  so  such  an 
action  tends  to  increase  rather  than  decrease  the  per  cent,  of 
saturation  of  the  total  porosity  of  the  rocks. 

The  influence  of  heat  resulting  from  the  expansion  and 
contraction  following  periods  of  burial  and  exposure  due  to 
erosion  can  be  no  effective  agent  in  removing  the  water  since 
water  increases  only  4  per  cent  in  volume  when  it  is  raised 
from  a  temperature  of  4  degrees  Centigrade  to  100  degrees 
Centigrade  and  this  represents  a  much  greater  change  in 
temperature  of  rock  strata  than  ever  occurs  in  a  geologic 
cycle. 

Drainage  in  an  area  of  the  nature  of  the  Alleghany  coal 
basin  is  not  possible  since  the  basin  is~  so  shaped  that  the 
water  cannot  drain  out  of  it.  Moreover,,  these  sands  are 
below  sea  level  and  hence  not  subject  to  drainage. 

Thus  with  no  adequate  explanation  of  how  sea  water  has 
been  removed  from  rock  strata  it  is  more  logical  to  consider 
the  water  present  to  be  of  connate  rather  than  of  meteoric 
origin. 

THE  ASSOCIATION  OF  THE  DRY  SANDS  AND  "  EED  BEDS  " 

A  study  of  the  non-water-bearing  strata  of  the  Appalachian 
oil  fields  has  furnished  data  which  is  to  be  interpreted  as 
furnishing  positive  evidence  that  the  waters  present  in  these 
sands  are  connate  in  origin.  As  mentioned  above  the  Cats- 
kill  and  certain  areas  of  the  Mississippian  sands  contain  no 
water.  This  absence  of  water  is  not  due  to  structural  or 
porosity  conditions  but  it  is  characteristic  of  sands  which  are 
associated  with  red  shales.  Several  lines  of  evidence  indicate 
that  these  dry  areas  and  the  "  red  beds  "  were  developed  when 
the  sediments  were  exposed  as  flood-plain  deposits  to  the  ac- 
tion of  air  which  oxidized  the  ferrous  minerals  present  and 
at  the  same  time  dried  out  the  sediments,  in  which  condition 
they  have  remained  to  the  present  time.  The  acceptance  of 
this  conclusion,  the  arguments  in  support  of  which  are  given 


62  Natural  Brines  of  Oil  Fields  [260 

elsewhere/   results   in   attributing  a  connate   origin  to   the 
water  present. 

THE  CHEMICAL  NATURE  OF  THE  WATER 

The  following  is  a  mean  analysis  of  8  brines  collected 
from  strata  of  Mississippian  age  expressed  in  parts  per 
million  parts  of  water : 

Si02  137  Na                    41585 

Fe  26  K                          307 

Ca  12740  Br                           44 

Mg  2295 

Hc03  19                             Total          153000  parts  of 

S04  1530  dissolved  matter  per  million 

Cl  95043  parts  of  water 

The  outstanding  feature  of  the  water  is  its  high  chlorine 
content.  This  makes  up  about  the  entire  acidity  of  the  water 
and  comprises  61.12  per  cent,  of  the  total  dissolved  matter 
present.  The  other  negative  ions  present,  HC03  and  S04, 
occur  in  small  amounts,  making  up  but  about  one  per  cent, 
of  the  salts  present.  Sodium  is  by  far  the  most  abundant  of 
the  basic  ions  and  comprises  21.18  per  cent,  of  the  material 
in  solution.  Calcium  is  about  one-third  as  abundant  as  so- 
dium and  consists  of  8.33  per  cent  of  the  total  salts  present. 
The  other  basic  ions  occur  in  unimportant  amounts. 

In  addition  to  their  peculiar  chemical  nature  the  brines 
are  also  to  be  distinguished  by  their  concentration,  which  is 
from  three  to  seven  times  as  great  as  ocean  water.  Another 
interesting  feature  is  the  similarity  in  content  of  the  consti- 
tuents carried  by  the  waters.  Reference  to  the  analysis  on 
page  will  show  that  the  various  salts  are  always  present 
in  about  the  same  relative  amounts.  This  is  the  more  strik- 
ing when  it  is  considered  that  the  waters  were  collected  at 
points  over  an  area  of  10,000  square  miles  and  from  horizons 
of  different  geologic  age  occurring  at  depths  of  from  1000  to 


beeves,  Frank:  A  Discussion  of  the  Absence  of  Water  in  Certain 
Petroleum-bearing  Strata  of  the  Appalachian  Oil  Fields.  Disserta- 
tion in  Johns  Hopkins  University  Library. 


261] 


F.  Reeves 


63 


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Graphs  showing  the  amount  of  each  ion  (expressed  in  per  cent,  of 
the  total  salts  present)  in  the  brines  collected  from  Pennsylvania, 
Mississippi,  Catskill  and  Lower  Devonian  strata  and  in  the  average 
Ocean  (O)  and  river  waters  (R)  of  the  world. 


64  Natural  Brines  of  Oil  Fields  [262 

6000  feet.  A  slight  change  in  chemical  nature  with  depth 
is  noticed  which  may  be  a  function  of  stratigraphic  horizon. 
This  possibility  will  be  discussed  later. 

Obviously  the  brines  are  not  like  ocean  waters  yet  they 
are  more  unlike  surface  waters  and  since  they  are  to  be  con- 
sidered as  originating  from  one  of  these  sources  it  is  logical 
to  attribute  them  to  that  one  which  they  more  nearly  resem- 
ble as  this  requires  the  explanation  of  fewer  anomalies  in 
the  transition  from  the  one  water  to  the  other. 

This  comparison  is  shown  graphically  on  page  63.  On 
the  horizontal  lines  P,  M,  C,  D,  are  plotted,  in  percentage  of 
total  salts  present,  the  amount  of  each  ion  in  the  four  mean 
analyses  of  the  brines  from  the  sands  of  the  Pennsylvanian, 
Mississippian,  Catskill,  and  Lower  Devonian,  respectively. 
On  line  S  is  plotted  also  the  percentages  of  the  salts  in 
the  mean  analyses  of  ocean  and  surface  waters.  With  a  line 
drawn  through  these  points  a  clear  idea  is  obtained  of  the 
similarity  between  the  brines  and  their  two  possible  sources. 

On  the  assumption  that  the  brines  are  surface  waters  which 
owe  their  present  chemical  nature  to  changes  which  they  have 
undergone  as  they  passed  downward  through  the  rock  ma- 
terial, it  would  be  expected  that  with  increase  of  depth  there 
would  be  a  progressive  change  at  least  to  a  point  of  satura- 
tion. Thus,  for  example,  since  there  is  a  decrease  say  of 
calcium  in  the  first  1300  feet  of  from  20.39  per  cent,  to  8-33 
per  cent.,  at  greater  depth  it  would  be  expected  that  the 
deeper  brines  would  continue  to  show  a  decrease  in  the 
amount  of  this  ion  present.  Reference  to  the  graph  shows 
that  instead  there  is  a  decided  increase  of  calcium  with  in- 
crease in  depth  below  1300  feet.  Sodium  shows  the  same 
anomalous  change  with  depth.  It  is  apparent,  on  the  other 
hand,  that,  with  the  exception  of  magnesium,  the  ocean 
waters  fall  more  in  the  general  alignment  of  the  graphs  than 
do  the  surface  waters.  Of  course  it  may  be  argued  that  the 
water  would  undergo  a  greater  chemical  change  in  the  surface 
strata  or  in  the  zone  of  oxidation  than  at  subsequent  depths, 


263] 


F.  Reeves 


ater 
water 


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Dev.     0  £ 


Mississippi 


65 
Pennsylvanian 


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66  Natural  Brines  of  Oil  Fields  [264 

but  it  is  hardly  possible  that  the  reactions  between  the 
waters  and  the  rock  material  would  produce  a  brine  so  simi- 
lar to  ocean  water,  since  the  alteration  of  river  water  to  ocean 
water  is  effected  largely  by  the  action  of  organisms  in  the 
sea. 

The  perpendicularity  of  the  lines  uniting  the  brines  and 
the  ocean  water  indicate  the  similarity  between  the  chemical 
nature  of  the  present  ocean  and  that  of  former  seas.  The 
variations  from  the  straight  line,,  with  the  exception  of  the 
graphs  for  calcium  and  sodium,  is  readily  explained  by  the 
possible  reactions  which  may  have  occurred  between  the  rock 
material  and  the  chemicals  in  solution.  It  will  be  noted, 
however,  that  there  is  a  definite  increase  of  calcium  and 
decrease  in  sodium  in  passing  downward  from  the  Pennsyl- 
vanian  to  the  Lower  Devonian  brines.  If  the  waters  are 
assumed  to  be  of  meteoric  origin,  then  there  is  the  anomaly 
of  the  more  soluble  sodium  being  replaced  by  the  less  soluble 
calcium  ion  as  the  water  penetrates  the  earth's  crust.  If, 
however,  the  waters  are  considered  to  be  of  connate  origin, 
then  this  change  in  depth  may  be  a  function  of  the  geological 
age  of  the  strata  and  hence  indicate  changes  in  the  chemical 
content  of  the  ocean  during  different  geologic  periods. 

If  the  salts  of  the  ocean  have  been  added  by  the  rivers, 
then,  of  course,  the  salinity  of  the  ocean  would  increa.se  with 
the  age  of  the  earth.  This  increase  in  salinity  will  not  affect 
the  chemical  nature  of  the  water  if  the  relative  amount  of  each 
salt  remains  constant.  However,  since  organic  matter  and 
changes  in  physical  conditions  remove  some  salts  from  solu- 
tion, the  waters  will  change  in  nature  as  well  as  concentration. 
Thus  the  relative  increase  in  sodium  may  be  explained  by 
the  fact  that  but  little  of  the  enormous  amount  of  this  salt 
added  continually  by  the  rivers  is  lost  by  the  ocean,  while 
most  of  the  other  salts  are  constantly  being  removed  from 
solution.  The  variation  in  amount  of  calcium  in  the  differ- 
ent brines  is  likely  due  to  fluctuation  in  the  amount  of  C02 
in  the  air  during  different  geologic  periods.  This  fluctuation 


265]  F.  Reeves  67 

is  a  generally  accepted  fact 2  and  since  there  is  an  equilibrium 
between  the  amount  of  the  C02  in  the  air  and  in  the  sea 
water  it  is  to  be  expected  that  the  sea  water  at  times,  when 
there  is  the  greatest  amount  of  C02  in  the  atmosphere,  will 
hold  a  comparatively  larger  amount  of  calcium  in  solution 
as  the  solubility  of  calcium  carbonate  is  a  direct  function  of 
the  amount  of  C02  present.3 

The  increase  in  concentration  with  depth  is  also  an  argu- 
ment that  the  brines  are  indigenous  to  the  rocks  in  which 
they  occur.  Kichardson,4  however,  suggests  that  this  is  due  to 
the  fact  that  there  has  been  an  upward  diffusion  of  salts  from 
the  rock  salt  deposits  that  are  known  to  underly  the  strata 
in  question.  But  it  has  been  pointed  out  that  there  are  dry 
sands  in  the  area  under  consideration  intervening  between 
these  lower  water-bearing  horizons  and  the  Mississippian 
sands  and,  as  diffusion  through  dry  strata  is  impossible,  this 
suggestion  seems  untenable.  Again,  on  this  assumption  it  is 
difficult  to  understand  why  sodium  would  increase  in  relative 
amount  with  increase  in  distance  from  the  salt  beds.  Refer- 
ence to  the  analysis  given  will  show  that  the  Pennsylvanian 
brines  are  richer  in  this  salt  than  the  Lower  Devonian.  It 
appears  more  likely  that  the  concentration  is  due  to  a  capil- 
lary migration  of  the  water  away  from  the  sands  in  which  it 
occurs  and  in  which  it  accumulated.  This  migration  would 
remove  part  of  the  water  and  most  likely  leave  the  salt  behind, 
because  fine-grained  sediments  have  an  absorptive  effect  on 
solutions  passing  through  them  5  which  would  result  in  a 


2  Chamberlain,  T.  C.     "  The  influence  of  great  epochs  of  limestone 
formation  on  the  constitution  of  the  atmosphere."     Jour.  Geol.,  vol. 
vi,  1898,  pp.  609-621. 

3  Johnson,  John  and  Williamson,  E.  D.     "The  rOle  of  inorganic 
agencies  in  the  deposition  of  calcium  carbonate."     Jour.  Geol.,  vol. 
xxix,  No.  8,  1916,  pp.  729-750. 

4  Richardson,  G.  B.     "  Note  on  the  diffusion  of  sodium  chloride  in 
Appalachian  oil  field  waters."    Jour.  Wash.  Acad.  Sci.,  vol.  vii,  no.  3, 
1917,  pp.  73-75. 

6  Turrentine,   J.   W.     "  The   occurrence   of  potassium   salts   in   the 
saline  of  the  United  States."    Bureau  of  Soils,  Bull.  94,  1913. 


68  Upper  Cretdceous  Seacoast  in  Montana         [266 

greater  concentration  of  the  waters.  Considering  this  fact, 
then,  the  waters  should  show  a  decrease  rather  than  an  in- 
crease of  mineral  matter  with  depth,  if  the  waters  were  of 
surface  origin.  Which  adds  more  evidence  to  the  above,  that 
these  natural  brines  are  of  connate  origin. 


AN  UPPER  CRETACEOUS  SEACOAST  IN  MONTANA1 

By  W.  T.  THOM,  JR. 


INTRODUCTION 

The  nonpersistence  of  lithologic  units  is  the  greatest  ob- 
stacle to  systematic  stratigraphic  work  and  correlation.  Par- 
ticularly is  this  true  when  it  is  necessary  to  determine  the 
relationship  of  marine  and  continental  deposits.  That  this 
difficulty  may  be  largely  overcome  by  a  correct  "  paleophysio- 
graphic  "  perspective  of  the  period  dealt  with  is  now  becoming 
the  accepted  doctrine ;  and  the  writer  has  undertaken  this 
sketch  both  as  an  illustration  of  the  way  in  which  ancient 
physiographic  conditions  may  be  deciphered  and  as  a  demon- 
stration of  the  close  genetic  relationship  of  some  of  the  differ- 
ent lithologic  phases  of  the  Judith  River  formation. 

The  writer  studied  this  formation  in  the  area  lying  north 
of  the  Yellowstone  Biver,  near  Billings,  Mont.,  while  serving 
as  an  assistant  to  Eugene  T.  Hancock,  of  the  United  States 
Geological  Survey,  and  it  is  with  his  very  kind  consent  that 
this  article  is  published.  The  accompanying  sketch  map  will 
serve  as  a  geographic  guide  to  the  reader  in  following  the 
discussion. 

STRATIGRAPHIC  GEOLOGY 

The  later  Upper  Cretaceous  sediments  of  the  Montana 
group  are  exposed  throughout  this  region,  forming  about  90 


1  Published  by  permission  of  the   Director   of  the  United  States 
Geological  Survey. 


167] 


W.  T.  Thorn 


69 


per  cent,  of  the  rocks  outcropping  within  its  limits.  Five 
formational  subdivisions  of  the  Montana  are  present,  which 
are,  in  ascending  order,  the  Eagle  sandstone,  Claggett  shale, 
Judith  Eiver  formation,  Bearpaw  shale,  and  Lennep  sand- 
stone. The  relationship  of  these  units  is  perhaps  best  brought 
out  by  the  accompanying  diagram,  but  a  brief  description  of 
each  formtion  may  make  the  details  clearer. 

The  Eagle  sandstone  is  developed  in  this  area  as  the  marine 
sandstone  apex  of  a  wedge  of  continental  sediments  built  sea- 
ward at  the  close  of  Colorado  time.  The  strand  origin  of  the 


FIG.  1.     Sketch  map  of  an  area  in  Montana. 

upper  part  of  the  formation  seems  clearly  indicated  by  abun- 
dant impressions  of  the  fossil  seaweed  Halymenites  major,  by 
the  coarse  grain  of  the  sandstone,  and  by  the  almost  universal 
distribution  of  small,  flattened  chert  pebbles  at  or  near  the 
top  of  the  formation.  The  Judith  Eiver  formation  is  much 
like  the  Eagle  in  mode  of  origin,  but  is  thicker  and  shows  the 
development  of  fresh-water  and  estuarine  phases  much  farther 
east  than  the  Eagle.  The  Lennep  sandstone  constitutes  a 
third  continental  wedge,  chiefly  notable  for  the  predominance 
of  volcanic  material  among  its  component  sediments.  Separ- 
ating these  strand  and  coastal-plain  deposits  are  the  marine 
shales  of  the  Claggett  and  Bearpaw  formations,  which  thin 
westward  and  disappear  at  an  indeterminate  distance  beyond 
the  border  of  the  area  under  consideration. 


70  Upper  Cretaceous  Seacoast  in  Montana         [268 

From  this  and  from  other  evidence  at  hand  it  seems  rea- 
sonably certain  that  the  strand  lines  of  the  late  Mesozoic  lay 
nearly  parallel  to  the  present  Eocky  Mountain  front,  and 
that  it  migrated  to  and  fro  in  response  to  the  recurrent 
depressive  movements  of  the  period,  which  were  gradually 
counterbalanced  by  intervening  intervals  of  sedimentation. 

DISTRIBUTION  AND  CHARACTER  OF  THE  JUDITH  RIVER  SEDI- 
MENTS 

The  sediments  of  the  Judith  River  formation  are  now  well 
exposed  north  of  Billings  by  reason  of  the  extensive  denuda- 
tion which  the  region  has  undergone;  hence  it  is  possible  to 
form  an  accurate  estimate  of  the  variations  of  the  section, 
both  vertically  and  horizontally. 

Near  Gibson,  50  miles  northwest  of  Billings,  the  formation 
is  of  freshwater  origin  and  consists  of  sandy  .shale  and  nu- 
merous beds  of  hard,  rather  muddy,  quartizitic  sandstone 
containing  reed  stems  and  fragments  of  coniferous  material. 
Both  shale  and  sandstone  are  characteristically  of  a  yellowish 
or  tawny  hue,  though  some  of  the  beds,  particularly  among 
the  softer  units,  indicate  by  their  texture  and  peculiar  green- 
ish brown  color  the  presence  of  the  tuffaceous  material  which 
was  thrown  out  so  copiously  by  the  volcanoes  of  the  Crazy 
Mountains  during  later  Upper  Cretaceous  and  early  Eocene 
time. 

Farther  east  the  volcanic  material  disappears  and  the  sec- 
tion gradually  assumes  the  aspect  typical  of  the  formation  as 
it  is  developed  along  the  Missouri  and  in  the  vicinity  of 
Havre  on  Milk  River;  an  alternation  of  light-gray  to  white 
clay  shales  with  lignitic  shale  and  carbonaceous  sandstone 
giving  the  exposures  a  peculiar  striped  appearance.  With 
the  advent  of  the  carbonaceous  zones  in  the  section  the 
brackish  water  shell  Ostrea  subtrigonalis  also  makes  its  ap- 
pearance at  different  horizons  in  the  area  immediately  north 
of  Broadview,  though  it  is  conspicuously  present  in  but  a 
single  very  thick  shell  bed  of  extraordinary  uniformity  and 


269]  W.  T.  Thorn  71 

persistence  of  development  which  lies  about  50  feet  above  the 
basal  sandstone  of  the  formation. 

At  Acton,  15  miles  northwest  of  Billings,  the  formation 
still  retains  its  characteristic  appearance  and  lithology,  but 
east  of  the  town  a  very  rapid  lateral  variation  of  the  sedi- 
ments soon  Incomes  apparent.  The  thin  carbonaceous  sand- 
stones of  the  western  section  rapidly  increase  in  magnitude 
and  in  coarseness  of  grain  to  the  eastward,  individual  mem- 
bers increasing  from  6  or  8  to  as  much  as  50  feet  in  thickness 
within  a  distance  of  5  miles.  As  a  result  the  formation,  as 
exposed  about  6  miles  east  of  Acton,  consists  of  four  massive 
sandstones  separated  by  intervals  of  shaly  sandstone  or  sandy 
shale.  Abundant  impressions  of  Halymenites  major  occur 
throughout  these  sandstones  and  indicate  the  inception  of 
strand  conditions,  a  conclusion  confirmed  by  the  discovery 
of  marine  fossils  a  few  miles  farther  east,  near  Huntley. 

From  where  the  maximum  of  sandstone  development  is 
attained,  6  miles  east  of  Acton,  the  lower  sandstone  members 
begin  to  taper  eastward,  merging  into  shale  lithologically 
indistinguishable  from  that  of  the  underlying  Claggett. 

It  is  further  to  be  noted  that  certain  surprising  features 
of  the  Judith  River-Bearpaw  contact  appear  southeast  of 
Gibson.  Long,  narrow  ridges  capped  by  hard  andesitic  sand- 
stone are  developed  for  considerable  distances,  especially  near 
Big  Lake  in  the  so-called  Lake  Basin  region,  their  general 
extension  being  from  east  to  west  or  from  southeast  to  north- 
west. The  cap  sandstones  of  these  ridges  were  probably 
never  continuous  over  the  intervening  areas,  but  they  lie  at 
practically  an  identical  horizon  and  are  so  similar  lithologi- 
cally that  they  are  certainly  the  products  of  the  same  agency. 

Below  these  upper  dark  sandstones  the  section  shows 
great  variability;  at  some  localities  sandy  beds  containing 
more  or  less  carbonaceous  shale  and  lignite  occupy  the  whole 
of  the  interval  down  to  the  more  typical  Judith  River  sedi- 
ments, while  elsewhere,  even  in  the  same  ridge,  the  cap 
sandstone  may  overlie  typical  Bearpaw  shale  with  only  a 


72 


Upper  Cretaceous  Seacoast  in  Montana         [270 


few  feet  of  thin-bedded  white  sandstone  intervening.  From 
this  and  from  other  corroborative  evidence  the  conclusion 
therefore  seems  natural  that  the  ridges  represent  the  radiat- 
ing channel  sandstones  of  an  ancient  delta,  which  was  built 
out  into  the  marine  waters  of  the  incipient  Bearpaw  sea  by 
a  river  of  considerable  size  flowing  from  the  south  or  south- 
west. 


MONTANA 


Colorado 


FIG.  2.     Section  showing  the  relation  of  the  sediments. 

PALEO GEOGRAPHIC  INTERPRETATION 

Upon  the  basis  of  the  foregoing  data  the  writer  draws  the 
following  picture  of  the  physiography  of  Judith  River  time. 

The  low  coastal  plain  of  the  mainland  lay  to  the  east  of  the 
Crazy  Mountains,  very  possibly  extending  thence  a  little 
beyond  Gibson,  and  upon  it  a  gradually  increasing  thickness 
of  freshwater  and  subaerial  deposits  was  laid  down  as  regional 
subsidence  progressed.  Simultaneously  a  sandy  barrier  beach 
was  developed  and  maintained  in  the  area  east  of  Acton,  thus 
partially  shutting  off  a  shallow  embayment  or  lagoon  whose 
quiet  waters,  rendered  brackish  by  the  regional  drainage, 


271]  W.  T.  Thorn  73 

afforded  a  favorable  habitat  for  multitudes  of  oysters,,  which 
were  later  buried  by  the  burden  of  fine  silt  accumulating  in 
the  quiet  waters  of  the  bay.  Still  later,  as  sedimentation 
gained  upon  subsidence,  the  site  of  the  one-time  oyste'r  bed 
became  the  location  of  repeated  coastal  swamps,  in  which 
were  formed  the  lignitic  beds  and  carbonaceous  zones  now  so 
conspicuous  in  the  upper  part  of  the  formation. 

Subsequent  revival  of  the  local  depressive  movements  of 
the  crust  temporarily  restored  the  old  embayment,  into  the 
southern  end  of  which  a  large  river  built  out  a  delta,  even  as 
the  marine  shales  of  the  Bearpaw  were  being  laid  down  in 
the  deeper  part  of  the  bay  a  little  farther  north.  As  a  final 
phase  more  rapid  depression  carried  marine  waters  farther 
westward,  and  the  Bearpaw  sea  covered  the  whole  area. 


A  REMARKABLE  UPPER  CRETACEOUS  FAUNA  FROM 

TENNESSEE  * 


By  BRUCE  WADE 


During  the  summer  of  1915  the  Tennessee  Geological 
Survey  located  well-preserved  fossils  in  the  Eipley  formation 
in  the  northeastern  part  of  MclSTairy  County,  Tennsesee.  An 
incomplete  collection  was  made  from  the  locality  in  this 
region  where  the  strata  containing  the  fossils  are  best  ex- 
posed. This  collection  was  studied  during  the  winter  in  the 
Geological  Laboratory  of  the  Johns  Hopkins  University. 
This  partial  study  of  the  fauna  has  resulted  in  the  differen- 
tiation of  nearly  300  species,  and  investigations  show  that  no 
single  locality  yet  reported  from  the  Cretaceous  of  North 
America  has  furnished  such  a  large  fauna  made  up  of  such 
well-preserved  shells. 

The  Gastropods  are  unusually  abundant  and  include  not  only 


1  Published  with  the  permission  of  Dr.  A.  H.  Purdue,  State  Geolo- 
gist of  Tennessee. 


74  Upper  Cretaceous  Fauna  from  Tennessee       [272 

a  large  number  of  new  species  but  several  forms  which  are 
regarded  as  new  genera.2  Further  collections  were  made  at 
this  place  and  in  the  adjoining  regions  during  the  field- 
season  of  1916.  The  writer  has  begun,  for  the  Tennessee 
Geological  Survey,  an  investigation  of  all  the  Upper  Cre- 
taceous deposits  of  the  state  and  hopes  to  submit  in  the  near 
future  a  detailed  report  on  the  Stratigraphy  and  Systematic 
Paleontology  of  these  rocks. 

GENERAL  GEOLOGICAL  EELATIONS. 

The  Upper  Cretaceous  deposits  of  Tennessee  outcrop  in  a 
wedge-shaped  area  which  crosses  the  State  in  a  nearly 
north  and  south  direction,  and  lies  largely  west  of  the  Ten- 
nessee Eiver  in  the  west-central  part  of  the  State.  This  area 
is  about  67  miles  wide  along  the  southern  boundary  of  the 
State,  narrowing  to  the  northward  until  at  the  Kentucky 
line  it  is  only  about  15  miles  in  width.3  Along  the  southern 
border  of  the  State  in  Wayne,  Hardin,  McNairy  and  Harde- 
man  counties  these  deposits  may  be  segregated  into  the  fol- 
lowing lithologic  units. 

f  Owl  Creek  horizon 

-r>.  ,       „  !  McNairy  sand  member 

Eipley  formation  J  _  .      . 

]  Ferruginous  clay  horizon 

[Coon  Creek  horizon 
Selma  chalk 
Eutaw  formation 
Tuscaloosa  formation 

The  present  discussion  is  limited  to  the  lower  part  of  the 
Eipley.  This  formation  covers  the  western  two-thirds  of 
McNairy  County,  and  in  general  is  well  exposed  over  that 
entire  region.  The  four  horizons  or  members  of  the  Eipley 


2  Some  of  these  have  been  described  in  the  Proc.  Phila.  Acad.  Nat. 
8ci.,  1916,  pp.  455-471,  pi.  23,  24. 

3  Jenkins,  0.  P.,  Geological  Map  of  Tennessee,  State  Geol.  Survey, 
1915. 


273]  B.  Wade  75 

named  above  may  be  traced  across  the  county  by  their  con- 
tained faunas  and  lithology,  even  though  there  are  no  sharp 
lines  of  demarcation  separating  the  one  from  the  other.  The 
sediments  of  the  Coon  Creek  horizon,  which  are  described  in 
detail  below,  are  quite  variable,  ranging  from  local  lenses  of 
impure  limestone  through  very  fossiliferous  marls  to  glau- 
conitic  sands  and  gypsiferous  clays  poor  in  fossils.  The 
overlying  ferruginous  clay  horizon  is  sparsely  fossiliferous 
and  extends  across  the  county  in  a  belt  about  three  miles 
wide.  The  McNairy  sand  member  next  above,  which  is 
typically  exposed  in  McNairy  county,  has  been  described  by 
Stephenson.4  This  member  is  essentially  a  sand  and  has 
yielded  few  fossils.  The  so-called  fucoid  Halymenites  major 
Lesq.  occurs  sparingly.  In  1915  leaves  were  collected  from 
near  Selmer,  Tenn.,  and  Big  Cut,  Tenn.,  the  type  section  for 
this  number.  These  have  been  submitted  to  Prof.  E.  W. 
Berry  for  study.  Above  the  McNairy  sand  and  exposed 
along  southwestern  McNairy  County  and  southeastern  Har- 
din  County  is  a  fossiliferous  horizon  which  may  be  traced 
southward  into  Mississippi  to  Owl  Creek,  the  type  locality  for 
the  Ripley  formation. 

COON  CREEK  LOCALITY  AND  ITS  STRATIGRAPHIC  POSITION. 

The  locality  under  immediate  discussion  may  be  known  as 
the  Dave  Weeks  place  on  Coon  Creek.  It  is  in  the  north- 
eastern part  of  McNairy  County,  3%  miles  south  of  Enville 
and  7%  miles  north  of  Adams ville  and  %  mile  east  of  the 
main  Henderson-Adamsville  Road.  The  beds  containing  the 
fossils  are  best  exposed  in  the  valley  about  two  hundred  and 
fifty  yards  east  of  Dave  Weeks'  house  along  the  headwaters  of 
Coon  Creek.  This  is  a  small  .stream  flowing  northward  into 
White  Oak  Creek,  a  tributary  of  the  Tennessee  River. 

Upper   Cretaceous   fossils   have   been   previously   collected 


4  Stephenson,  L.  W.,  U.  S.   Geological  Survey,    1914,   Prof.  Paper 
81,  p.  22. 


76  Upper  Cretaceous  Fauna  from  Tennessee       [274 

from  a  few  places  in  this  general  region  of  the  Mississippi 
radius  of  7%  miles  of  the  Dave  Weeks'  place.  At  a  point  % 
mile  west  of  Adamsville  Stephenson 5  made  a  collection  from 
the  Exogyra  ponderosa  zone  of  the  Selma  chalk.  Four  miles 
northeast  of  Adamsville  he  made  another  collection  from  the 
same  zone  at  a  locality  referred  to  as  "  four  miles  southwest 
of  Coffee  Landing."  Three  miles  west  of  Adamsville  fossils 
were  found  by  Stephenson  in  the  Exogyra  costata  zone  of  the 
Selma  chalk.  About  eleven  miles  southwest  of  the  Coon 
Creek  locality  and  "two  and  one-half  miles  east  of  Purdy," 
Safford6  collected  in  the  uppermost  part  of  the  formation 
which  he  designated  as  the  "  Green  Sand."  The  horizon 
from  which  this  last  collection  was  made  probably  has  the 
same  stratigraphic  position  as  the  Coon  Creek  beds.  The 
best-known  fossil  locality  in  this  general  region  is  the  classic 
Owl  Creek  locality 7  in  Tippah  County,  Mississippi,  often  re- 
ferred to  in  the  literature  as  Ripley,  Mississippi.  (See  sketch 
map,  Fig.  1.) 

A  sketch  map  has  been  inserted  on  page  77  to  show  the 
location  of  Coon  Creek  and  Owl  Creek  and  to  give  in  a 
general  way  the  areal  geology  in  the  region  about  these 
localities.  Big  Cut  and  Coffee  Landing,  two  other  impor- 
tant localities  in  the  Cretaceous  Geology  of  Tennessee  are 
shown  on  this  map.  The  information  given  on  the  map  south 
of  the  Tennessee-Mississippi  line  has  been  furnished  by  Dr. 
L.  W.  Stephenson  of  the  United  States  Geological  Survey. 

The  Coon  Creek  horizon  is  stratigraphically  near  the  base 
of  the  Eipley  formation  and  in  the  Exogyra  costata  zone. 


«Idem.,  p.  24. 

6  Safford,  J.  M.,  Geology  of  Tennessee,  1869,  p.  416. 

7  Conrad,  T.  A.,  Jowr.  Acad.  Nat.  8ci.,  Philadelphia,  1858,  vol.  iii, 
2d  ser.,  pp.  323-336. 

Conrad,  T.  A.,  Jour.  Acad.  Nat.  Sci.,  Philadelphia,  1860,  vol.  iv, 
2d  ser.,  pp.  275-298. 

Stephenson,  L.  W.,  U.  S.  Geological  Survey,  1914,  Prof.  Paper  81, 
p.  24,  table  2. 


B.  Wade 


7'7 


The  Selma-Eipley  contact  is  well  established  at  Blue  Cut  on 
the  Mobile  and  Ohio  Eailroad  at  the  state  line  on  the  south- 
ern extremity  of  McNairy  County.  From  this  point  the  con- 


FIG.  1.     Map  showing  the  areal  geology  of  a  portion  of  Tennessee 

and  Mississippi. 

1,  McNairy   Sand  Member;    2,   Ripley   Formation;    3,   Selma  Chalk; 
4,   Eutaw;    5,   Tuscaloosa. 

tact  may  be  readily  traced  both  by  lithological  and  faunal 
relations  to  Coon  Creek.  It  is  thus  evident  that  the  Coon 
Creek  horizon  lies  just  above  the  Selma  chalk  and  at  the 
base  of  the  Eipley.  The  Coon  Creek  horizon  is  thus  strati- 


78  Upper  Cretaceous  Fauna  from  Tennessee       [276 

graphically  lower  than  that  along  Owl  Creek  in  Mississippi. 
At  the  latter  locality  the  fossiliferous  horizon  is  in  the  upper- 
most beds  of  the  Eipley  and  is  directly  overlain  by  Eocene 
limestone.8  Below  the  Owl  Creek  beds  is  the  southern  equiv- 
alent of  the  McNairy  sand  member  of  the  Ripley  formation.9 
The  McNairy  sand  member,,  together  with  about  100  feet 
of  sparsely  fossiliferous,  ferruginous  Ripley  clay,  lie  strati- 
graphically  higher  than  the  Coon  Creek  horizon  and  are 
exposed  to  the  west  of  it.  (For  cartographic  relations  of  the 
two  localities  see  sketch  map  in  Fig.  1.)  Thus,  it  is  quite 
evident  that  the  Coon  Creek  fauna  is  older  than  the  Owl 
Creek  fauna. 

DESCRIPTION  OF  THE  LOCALITY  AND  CHARACTER  OF  THE 
SEDIMENT 

A  thickness  of  more  than  thirty  feet  of  the  fossil-bearing 
beds  is  exposed  along  the  banks  of  Coon  Creek.  For  one-third 
mile  this  stream  flows  in  a  narrow  V-shaped  channel  from 
six  to  fifteen  feet  deep  which  has  been  cut  out  during  the 
last  twenty  years.  The  stream  has  a  steep  gradient  and  its 
channel  is  deepened  by  every  heavy  rain.  The  channel  fills 
quickly  after  a  thundershower  and  its  sides  are  kept  freshly 
scoured  by  the  rushing  water.  White  shells  of  Crassatellites, 
Cucullaea,  Cyprimeria,  Gryphaea,  Ostrea,  Drilluta,  Lunatia, 
Baculites,  etc.,  project  out  of  the  dark  greyish  blue  matrix 
and  glitter  in  the  clear  water  and  the  sunshine.  In  general 
aspect  the  exposure  bears  a  striking  resemblance  to  certain 
Tertiary  beds.  In  broad  physiographic  relations,  character  of 
the  matrix  and  whiteness  of  the  shells,  the  Coon  Creek  locality 
resembles  the  well-known  Upper  Cretaceous  exposure  of 
Brightseat,  Maryland.  This  locality  is  two  miles  east  of  Dis- 
trict Line  and  has  yielded  the  most  prolific  Upper  Cretaceous 


8  Harris,  G.  D.,  The  Midway  Stage,  Bull.  Amer.  Pal,  vol.  4,  no.  4, 
1896,  p.  24. 

'Stephenson,  L.  W.,  Paper  given  before  the  Paleontological  So- 
ciety of  America,  December  29,  1916. 

Lowe,  E.  N.,  Geology  of  Mississippi,  Bull  12,  1915,  p.  62. 


277]  B.  Wade  79 

fauna  of  Maryland.  The  shells,  notably  the  bivalves,  are 
probably  more  abundant  at  Brightseat,  but  not  so  well  pre- 
served as  they  are  at  the  Tennessee  locality.  The  sediments 
containing  the  Coon  Creek  fauna  are  dark  bluish  green  and 
gray  clayey  sands.  The  sand  is  of  medium  fineness  and  con- 
sists of  angular  and  rounded  grains  of  quartz  as  the  major  con- 
stituent, with  glauconite,  small  flakes  of  mica,  and  shell  frag- 
ments as  minor  constituents.  Pieces  of  lignitic  wood  and 
small  nodular  masses  of  pyrite  are  common  but  not  abundant. 
All  of  the  above  elastics  are  cemented  together  with  a  fine 
calcareous  material,  forming  a  compact  impervious  mass 
which  varies  locally  in  arenaceous  and  argillaceous  content. 
There  is  locally  sufficient  lime  for  the  matrix  to  become  indu- 
rated into  a  very  hard,  impure  and  concretionary  limestone. 
When  this  marl  is  thoroughly  weathered  the  shells  are  re- 
moved leaving  casts  in  a  matrix  which  becomes  yellowish 
brown  in  color,  due  to  the  oxidation  of  the  glauconite  and 
other  ferruginous  constituents.  Dr.  Paul  C.  Bowers,  Chief 
Chemist  for  the  Tennessee  Geological  Survey,  has  made  a 
careful  quantitative  analysis  of  this  marl  and  reports  the 
following  results : 

Si02 65.30 

AloO3   8.56 

Fe203    3.72 

FeO    1.72 

MnO    44 

CaO    7.10 

: 70 


ff\ 2-42 

P  0     trace 

2     5 

FeS2    45 

C02   5.15 

H20    5.45 

Carbon 09 

Total    .  ..101.00 


80  Upper  Cretaceous  Fauna  from  Tennessee       [278 

HISTORICAL  SKETCH 

The  well-preserved  fossils  of  the  Eipley  formation  attracted 
the  attention  of  the  early  geologists  and  impressed  them  very 
much.  In  1856  Conrad  X1  described  fifty-six  new  species  from 
Owl  Creek  and  made  the  following  observations  about  the 
fauna : 

"The  Cretaceous  strata  of  Mississippi  have  long  been  ob- 
served and  partially  noted  by  geologists  and  the  lamented 
Professor  Tuomey  has  described  a  number  of  their  fossil  con- 
tents. I  now  introduce  quite  a  distinct  group  of  shells,  which 
are  imbedded  in  a  different  matrix  compared  with  the  preva- 
lent cretaceous  marls,  green  sands  and  limestones.  The  dis- 
covery of  these  beautiful  organic  remains  is  due  to  the  inde- 
fatigable exertions  of  Dr.  W.  Spillman,  of  Columbus,  who 
has  forwarded  a  collection  of  specimens  more  or  less  perfect, 
consisting  of  nearly  sixty  species,  all  of  which  appear  to  be 
unpublished  except  Scaphites  conradi.  The  appearance  of 
these  shells  is  like  that  of  eocene  species  which  have  merely 
lost  their  animal  matter,  and  in  this  respect  are  very  unlike 
the  condition  of  similar  genera  in  the  contiguous  rocks  of  the 
same  era.  The  fossils  are  imbedded  in  a  sandy  marl  of  a 
dark  gray  color,  the  principal  constituents  of  which  are  fine 
scales  of  mica  and  grains  of  quartz  mixed  with  fragments  of 
small  shells;  and  though  some  of  the  very  thin  species  are 
distorted,  the  stronger  retain  their  original  shapes  and  are 
generally  very  perfect.  Species  of  Crassatetta,  Nucula  and 
Meretrix  have  the  valves  united  as  in  life,  as  well  as  a  few  of 
the  extremely  thin  Inocerami,  though  the  latter  are  more  or 
less  distorted  by  pressure.  The  numerical  proportion  of 
species  of  Cephala  and  Acephala  is  nearly  equal.  The  external 
sculpture  of  all  is  as  sharply  defined  as  in  existing  species. 
Besides  Scaphites  and  Baculites,  there  is  only  one  shell  in  the 
collection  which  resembles  a  species  of  the  green  sand  or  lime- 


11  Conrad,  T.  A.,  Jour.  Acad.  Nat.  8oi.,  Philadelphia,  2d  ser.,  vol. 
iii,  pp.  323-336. 


279]  B.  Wade  81 

stone,  and  it  is  quite  distinct.  The  rare  genus  Pulvinites  is 
herein  for  the  first  time  introduced  as  an  American  form. 
The  analogous  species,  as  well  as  that  of  Gervillia,  occur  in 
the  Baculite  limestone  of  France  and  Normandy,  which  I 
believe  is  referred  by  d'Orbigny  to  his  Senonian  Stage,  the 
same  in  which  he  included  the  Cretaceous  fossils  of  North 
America. 

"  It  is  interesting  to  find  bivalves  of  so  remote  an  era  in 
sufficient  preservation  to  exhibit  generic  characters  as  clearly 
defined  as  they  are  in  living  shells.  In  this  condition  are 
the  hinges  of  Gervillia,  Pulvinites,  Ctenoides  and  Cardium. 
Here  are  also  specimens  of  Baculites  and  Scaphites  which 
exhibit  the  interior  divested  of  all  extraneous  matter,  and 
delight  the  eye  with  exquisite  curves  of  the  foliated  septa, 
whilst  the  shells  glow  with  brilliant  iridescent  tints. 

"  This  beautiful  series  of  Cretaceous  forms  seems  to  be  very 
limited  in  geographical  distribution,  so  far  as  our  present 
knowledge  extends.  It  is  probably  unknown  as  yet  beyond 
the  limits  of  Tippah  County,  which  borders  on  Tennessee. 
No  account  has  been  given  of  such  a  group  by  the  State 
Geologists  of  Tennessee  or  Alabama.  Dr.  Spillman  informs 
me,  '  The  fossils  you  have  now  under  examination  were  found 
in  the  bluffs  of  Owl  Creek,  three  miles  north  of  the  town  of 
Ripley,'  and  he  concurs  in  opinion  with  me  that  they  might 
properly  be  named  the  '  Ripley  group.'  He  also  remarks  that 
Ammonites  placenta  occurs  in  it  with  the  shell  preserved,  and 
that  in  connection  with  the  Ripley  group,  or  in  the  same 
locality,  are  ' Exogyra  costata,  Gryphaea  mutabilis,  Ostrea 
plumosa,  Natica  petrosa,  Nautilus  DeKayi,  etc.,  with  the  shells 
more  or  less  preserved,  in  an  argillo-calcreous  marl/  but  none 
of  these  species  are  contained  in  his  collections  sent  me  from 
Tippah  County/'— Conrad,  1858. 

After  this  announcement  of  the  discovery  of  well  preserved 
Cretaceous  fossils  in  northern  Mississippi  was  made  by  Con- 
rad, Safford  collected  a  few  Ripley  fossils  from  near  Purdy, 
Tennessee  and  Tuomey  made  a  large  collection  of  unusually 
well  preserved  shells  at  Eufaula,  Alabama,  from  the  same 

6 


82  Upper  Cretaceous  Fauna,  from  Tennessee       [280 

horizon  as  Owl  Creek.  These  collections  were  sent  to  Conrad 
and  Gabb  for  study  and  their  contributions  appeared  in  1860 
in  Volume  IV  of  the  Journal  of  the  Philadelphia  Academy  of 
Natural  Sciences.  In  this  volume  Conrad  described  fifty-four 
additional  new  species  and  Gabb  four  new  species  collected 
from  northern  Mississippi,  Alabama  and  Tennessee.  Since 
the  work  of  these  men,  very  little  has  been  done  on  this  un- 
usually prolific  fauna.  Geologists  have  often  visited  Owl 
Creek  and  collections  have  been  made  but  nothing  has  been 
published  on  the  systematic  paleontology  except  for  minor 
contributions.12  The  most  recent  check  list  of  the  Eipley 
collections  in  the  National  Museum  from  this  region  is  that 
published  by  Stephenson  in  1914.13 

STATE  OF  PRESERVATION  OF  FOSSILS 

A  comparison  of  specimens  from  the  Coon  Creek  collection 
with  forms  from  Owl  Creek  in  the  National  Museum  shows 
that  the  shells  from  the  former  locality  include  many  small 
and  fragile  individuals,  and  that  many  individuals  present 
delicate  shell  parts,  internal  and  external  markings  not  so 
well  defined,  or  entirely  absent  in  the  Tippah  County  Speci- 
mens. The  hinge  areas,  muscle  scars,  buttresses,  pallial  lines 
and  external  sculpture  are  as  sharp  and  as  well  defined  in 
such  genera  as  Cucullaea,  Glycymeris,  Crassatellites,  Nucula, 
Cardium,  Trigonia,  Paranomia,  etc.,  as  in  the  shells  of  Ter- 
tiary and  Eecent  bivalves.  Even  the  ligaments  are  occasion- 
ally preserved  and  in  their  natural  positions  in  attached 
valves  of  Cardium  n.  sp.  Cyprimeria  n.  sp.  and  Leptosolen 
biplicata  Conrad.  Many  of  the  Gastropoda,  including  species 
of  such  genera  as  Liopeplum,  Gyrodes,  Ptychosyca,  Voluto- 
morpha,  Pugnellus,  etc.,  are  brilliantly  glazed.  The  shells  of 
Eutrephoceras,  Baculites,  Scaphites,  and  Turrilites  are  well 


12  Ball,  1890,  Trans.  Wagner  Free  Inst.  Sci.,  Philadelphia,  vol.  iii, 
pt.  1,  p.  73. 

Ball,  1907,  Smiths.  Misc.  Coll.,  vol.  iv,  pt.  1,  pp.  1-23. 
"'Stephenson,  L.  W.,  loc.  cit.,  p.  24,  tables  1-9,  1914. 


281]  B.  Wade  83 

preserved  and  abundant  but  in  many  cases  have  been  crushed 
by  the  weight  of  the  superincumbent  sediments.  The  proto- 
conchs  are  well  defined  and  in  a  perfect  state  of  preservation 
on  many  of  the  Gastropoda,  especially  such  genera  as  Laxi- 
spira,  Volutod&rma,  Paladmete,  Thylacus  and  many  others. 
The  protoconch  is  present  and  sharply  differentiated  in  a 
new  species  of  Teinostama  which  is  strikingly  like  the  Mio- 
cene form  Teinostoma  nana  (Lea).  The  adult  itself  is  only 
a  little  more  than  1  mm.  in  its  greatest  dimension,  yet  the 
shell  and  protoconch  are  both  brilliantly  glazed  and  look  as 
fresh  as  if  they  were  Eecent.  The  small  and  fragile  Scapho- 
pod  Cadulus  obnutus  (Conrad)  is  abundant  and  perfectly 
preserved.  Such  over-specialized  and  projecting  shell  parts 
as  the  anterior  calcareous  tube  and  the  fringing  tubules  of  the 
genus  Clavagella,  and  the  spinose  and  flaring  outer  lips  of 
such  genera  as  Anchura,  Aporrhais,  Volutoderma,  etc.,  occur 
unbroken.  Fragments  of  non-lignitized  and  non-petrified 
wood  are  common  arid  resemble  Eecent  wood  in  state  of  pre- 
servation as  shown  by  weight,  color  and  woody  fiber. 

The  occurrence  of  so  many  perfect  shells  in  unconsoli- 
dated  sediments  as  old  as  the  Cretaceous  is  exceedingly  rare. 
Although  these  fossils  have  retained  their  original  charac- 
ters and  shell  material  many  of  them  are  soft  and  fragile  so 
that  some  care  is  necessary  in  collecting  and  preparing  them. 
They  are  easily  removed  from  the  strata  with  part  of  the 
matrix  attached.  This  serves  to  protect  the  specimens  in 
packing  and  shipping.  When  the  collected  material  dries  the 
sandy  matrix  may  be  readily  cleared  away,  leaving  most  of 
the  shells  hard  and  fairly  strong.  The  weaker  specimens  can 
be  made  harder  and  sufficiently  strengthened  to  withstand 
handling  and  the  effects  of  the  atmosphere  by  a  method  of 
preparing  which  is  used  here  in  the  Geological  Laboratory. 
After  all  foreign  matter  has  been  removed  from  the  shells 
they  are  soaked  about  four  minutes  in  paraffin  heated  to  the 
boiling  point.  The  hot  wax  permeates  the  shell  walls  and 
reinforces  them.  The  shells  are  darkened  slightly  by  the  wax 
but  otherwise  the  method  is  altogether  satisfactory. 


84  Upper  Cretaceous  Fauna  from  Tennessee       [282 

At  both  the  Owl  Creek  (Miss.)  and  Brightseat  (Md.)  lo- 
calities the  fossil  beds  occur  directly  below  the  Cretaceous- 
Eocene  contact.  This  contact  represents  a  long  interval  of 
erosion  during  which  the  shell  beds  were  at,  or  very  near,  the 
surface  and  were  probably  subjected  to  the  action  of  circu- 
lating meteoric  waters  which  had  a  disintegrating  effect  on 
the  shells.  The  abundant  springs  at  this  horizon  show  that 
during  late  Pleistocene  and  Eecent  times  this  uncomformable 
Cretaceous-Eocene  contact  has  furnished  an  easy  channel  for 
ground  waters  which  have  attacked  the  unpetrified  shells. 
At  Coon  Creek,  on  the  other  hand,  the  conditions  are  some- 
what different.  There  is  no  overlying  uncomformable  contact 
dircetly  above  the  fossil  beds  but  instead  there  is  a  great 
thickness  of  overlying  impervious  Eipley  clays.  The  shells 
were  sealed  up  by  the  Upper  Cretaceous  sea  in  compact,  cal- 
careous sandy  sediments  and  have  been,  it  seems  unaffected 
by  circulating  ground  waters  until  the  dawn  of  the  present 
physiographic  conditions.  Even  now  these  beds  are  so  imper- 
vious that  the  ground  water  does  not  penetrate  them,  as  is 
shown  by  the  fact  that  well-drillers  have  reported  the  strata 
perfectly  dry.  The  character  of  the  matrix  at  the  three  locali- 
ties is  essentially  the  same,  so  that  it  seems  reasonable  to 
assume  that  the  Coon  Creek  shells  are  well  preserved  because 
they  have  been  protected  from  circulating  ground  waters  the 
action  of  which  is  so  evident  in  most  Cretaceous  strata. 

OBSERVATIONS  ON  THE  FAUNA 

The  Coon  Creek  fauna  is  both  prolific  and  varied.  Four 
days  collecting  at  this  locality  yielded,  according  to  preli- 
minary determinations  a  fauna  of  134  genera  and  269  species, 
and  further  collecting  has  materially  increased  this  number. 
The  study  is  yet  incomplete  and  some  of  the  determinations 
are  merely  tentative  but  the  following  generalizations  may  be 
made.  In  the  134  genera  already  recognized  there  are,  exclu- 
sive of  the  Mollusca,  three  genera  of  Vertebrata  of  the  Class 
Pisces;  5  of  Arthropoda  of  the  Class  Eucrustacea;  9  genera 


283]  B.  Wade  85 

of  Molluscoidea  of  the  Class  Bryozoa;  1  genus  of  Echinoder- 
mata  of  the  Class  Echinoidea ;  2  of  Vermes ;  and  1  of  Coelen- 
terata  of  the  Class  Anthozoa.  The  Mollusca,  however,  are  by 
far  the  most  abundant.  In  this  group  there  are  49  genera 
and  110  species  of  Pelecypoda;  2  genera  and  3  species  of 
Scaphapoda;  60  genera  and  120  species  of  Gastropoda;  4 
genera  and  7  species  of  Cephalopoda. 

It  has  been  estimated  that  the  Eecent  east  coast  Molluscan 
fauna  of  the  Middle  Atlantic  States  includes  more  than  500 
species,  and  there  is  no  reason  to  suppose  that  the  Upper  Cre- 
taceous faunas  were  materially  less  prolific.  On  the  contrary, 
the  seas  were  warmer  and  conditions  more  favorable  to  mollus- 
can  life,  so  that  probably  not  more  than  one-half  the  entire 
fauna  has  been  discovered. 

The  Coon  Creek  fauna  flourished  near  the  head  of  the 
Mississippi  Embayment  and  in  about  the  same  latitude  as  the 
Middle  Atlantic  States.  It  was  probably  in  the  same  general 
climatic  zone  of  the  Cretaceous,  so  that  any  estimate  of  the 
east  coast  fauna  should  hold  for  the  northern  part  of  the 
Mississippi  Embayment  as  well.  The  evidence  afforded  by 
the  Coon  Creek  material  shows  that  the  above  estimate  is  not 
overdrawn  but  probably  conservative.  The  extent  of  the 
undescribed  fauna  is  indicated  by  the  fact  that  four  days  col- 
lecting at  Coon  Creek  has  yielded  in  the  Mollusca  alone  over 
100  new  species,  three  new  subgenera  and  eight  new  genera. 

The  families  and  genera  with  the  number  of  species  in  each 
are  as  follows  (a  preliminary  list  made  May,  1916)  : 

CLASS  PELECYPODA 
Order  Prionodesmacea 

Nfcculidae.      Nucula 3  species 

Ledidae.  Leda 2  species 

Yoldia  1  species 

Parallelodontidae.  Nemodon 3  species 

Cucullaea  4  species 

Arcidae.  Area  4  species 

Glycymeris  2  species 

Axinea  1  species 

Postligata  1  species 


86  Upper  Cretaceous  Fauna,  from  Tennessee       [284 

Perniidae.     Inoceramus 3  species 

Gervilliopsis     1  species 

Pteriidae.    Pteria    2  species 

Ostreidae.     Ostrea    8  species 

Exogyra 1  species 

Pycnodonte    1  species 

Gryphaeostrea     1  species 

Trigoniidae.     Trigonia     2  species 

Pectinidae.    Pecten    4  species 

Limidae.     Lima    2  species 

Anomiidae.    Paranomia    3  species 

Anomia    3  species 

Pulvinites    1  species 

Mytilidae.     Modiolus    i  species 

Lithophaga    3  species 

Crenella    2  species 

Dreisseniidae.    Dreissena     1  species 

Order  Anomalodesmacea 

Anatinidae.    Periplomya     1  species 

Anatimya   1  species 

Corimya    1  species 

Clavagellidae.     Clavagella     2  species 

Poromyacidae.    Liopistha    3  species 

Order  Teleodesmacea 

Pleurophoridae.     Veniella    1  species 

Crassatellitidae.     Crassatellites     4  species 

Astartidae.    Vetericardia    1  species 

Diplodontidae.     Tenea    3  species 

Cardiidae.     Ca'rdium    4  species 

Veneridae.      Cyclina 2  species 

Meretrix    4  species 

Legumen    2  species 

Cyprimeria    1  species 

Tellinidae.    Linearia 2  species 

Solenidae.     Leptosolen   1  species 

Mactridae.     Spisula     1  species 

Corbulidae.     Corbula     4  species 

Saxicavidae.    Panope 2  species 

Pholadidae.    Pholidea     2  species 

Teredinidae.     Teredo   4  species.14 

CLASS  SCAPHOPODA 

Dentaliidae.    Dentalium    2  species 

Siphonodentaliidae.     Cadulus     1  species 


14  Besides  the  above  named  genera  there  are  probably  two  others  in 
the  collection  whose  generic  relations  have  not  been  determined  on 
account  of  fragmentary  material. 


285]  B.  Wade  87 

CLASS  GASTROPODA 
Order  Opisthobranchiata 
Suborder  Tectibranchiata 

Acteonidae.    Acteon    5  species 

Tornatella    2  species 

Ringiculidae.     Ringicula    1  species 

Scaphandridate.     Cylichna     1  species. 

Order  Ctenobranchiata 
Suborder  Toxoglossa 

Cancellariidae.    Paladmete    3  species 

Mataxa 1  species 

Turritidae.     Turris    1  species 

Surcula     6  species 

Volutidae.     Volutoderma    3  species 

Volutomorpha    5  species 

Tectaplica    1  species 

Liopeplum     1  species 

Drilluta    : 2  species 

Ptychosyca    2  species 

Mitridae.     Mitra    1  species 

Vasidae.     Xancus     3  species 

Fusidae.     Fusus    2  species 

Subgenus  Anomalofusus 1  species 

Ornopsis     2  species 

Fasciolaridae.     Piestochilus    1  species 

Odontof usus     3  species 

Thaisidae.     Sargana    2  species 

Busyconidae.   Busycon    1  species 

Pyropsis    3  species 

Pyrif usus    3  species 

Buccinidae.    Hemifusus   1  species 

Hydrotribulus    2  species 

Nyctilochidae.     Tritonium    1  species 

Columbellariidae.     Columbellina     1  species 

Strombidae.     Pugnellus     1  species 

Rimella    1  species 

Aporrhaidae.    Aporrhais    6  species 

Anchura    2  species 

Suborder   Streptodonta 

Scalidae.     Pseudomelania    1  species 

Vermetidae.     Laxispira    1  species 

Turritellidae.     Turritella     8  species 

Naticidae.     Gyrodes    3  species 

Lunatia 2  species 

Capulidae.     Thylacus    1  species 

Littorinidae.     Littorina    .1  species 


88  Upper  Cretaceous  Fauna  from  Tennessee       [286 

Order  Aspidobranchiata 

Eulimidae.     Leiostraca     1  species 

Euomphalidae.     Hippocampoides     1  species 

Turbinidae.    Schizobasis 1  species 

Trochidae.     Solariella 2  species 

Umboniidae.     Teinostoma   1  species 

Delphinulidae.     Urceoabrum 1  species 

Liotai    3  species.15 

CLASS  CEPHALOPODA 
Order  Nautiloidea 

Nautilidae.     Eutrophoceras     1  species 

Order  Ammonoidea 

Lytoceratidae.     Baculites    3  species 

Turrilites 1  species 

Cosmoceratidae.     Genus  Scaphites   1  species 

Probably  the  most  significant  fact  revealed  by  the  above 
list  is  that  the  number  of  univalve  species  is  greater  than  the 
number  of  bivalve  species.  However,  all  three  orders  of  the 
Pelecypoda  are  well  represented.  Of  the  Order  Prionodes- 
macea  the  three  families  represented  by  the  greatest  number 
of  forms  are  the  Arcidae,  Ostreidae  and  Mytilidae.  The  last 
two  had  their  beginning  in  the  Paleozoic.  The  Arcidae  ori- 
ginated and  suddenly  became  a  prominent  group  in  the  latter 
part  of  the  Mesozoic  and  developed  into  very  great  import- 
ance in  the  Tertiary.  Each  of  these  three  families  is  repre- 
sented by  four  genera  at  Coon  Creek.  Among  the  Anomalo- 
desmacea  there  are  three  families  and  five  genera.  The 
Teleodesmacea  are  well  represented.  Of  this  order  probably 
the  individuals  of  the  families  Cardiidae,  Veneridae,  and 
Corbulidae  are  most  abundant.  A  comparison  of  the  above 
list  with  lists  from  the  East  Coast  Cretaceous  shows  that  the 
bivalves  are  relatively  less  abundant  in  the  Coon  Creek  hori- 
zon than  in  corresponding  horizons  in  New  Jersey  and  the 
Middle  Atlantic  States.  Several  genera  such  as  Cuspidaria, 


15  Besides  the  above  named  genera  there  are  probably  thirteen 
genera  and  more  than  that  number  of  species  whose  generic  relations 
have  not  been  determined  on  account  of  the  fragmentary  condition 
of  the  material. 


287]  B.  Wade  89 

Myrtaea,  Phacoides,  Docinia,  Tellina,  Solyma,  etc.,  are  absent 
from  the  present  McNairy  County  collection  though  it  is 
probable  that  further  collecting  may  reveal  some  of  them. 

The  Scaphopoda  are  represented  by  the  two  families  Den- 
taliidae  and  Siphonodentaliidae.  The  former  originated  in 
the  Ordoviciari  and  are  abundantly  developed  in  the  Creta- 
ceous and  Tertiary.  They  are  represented  at  Coon  Creek  by 
one  genus  and  two  species,  one  of  which  is  very  common. 
The  family  Siphonodentaliidae  is  first  found  in  the  Creta- 
ceous. At  Coon  Creek  it  is  abundantly  represented  by  the 
minute  form  Cadulus  obnutus  (Conrad). 

The  Gastropoda  are  the  most  interesting  class  in  the  Coon 
Creek  fauna.  It  will  be  noted  from  the  list  given  above  that 
the  number  of  genera  and  species  of  the  Gastropoda  is  con- 
siderably greater  than  the  number  of  the  Pelecypoda,  yet, 
probably  in  every  cubic  yard  of  the  Coon  Creek  sediments 
the  number  of  bivalve  individuals  exceeds  the  univalve  indi- 
viduals several  times.  In  all  the  faunas  previously  reported 
from  the  Cretaceous  of  Eastern  United  States  the  bivalve 
species  are  more  numerous  than  the  univalve  species.  This 
majority  among  the  latter  may  be  due  simply  to  the  fact  that 
in  the  Upper  Cretaceous  seas  of  those  regions  the  pelecypods 
predominated  in  number  of  species  as  well  as  individuals,  or 
it  may  be  that  a  greater  number  of  gastropod  species  existed 
in  all  the  Cretaceous  seas  but  were  not  preserved  sufficiently 
to  be  recovered  from  the  sediments.  The  chance  of  preser- 
vation of  gastropod  shells  is  not  as  good  as  it  is  for  pelecy- 
pods, first,  because  the  number  of  individuals  per  species  of 
the  Gastropoda  is  rarely  ever  as  great  as  it  is  among  the 
Pelecypoda.  Second,  the  essential  constituent  of  univalve 
shells  is  aragonite,  and  this  mineral  is  much  less  stable  than 
calcite,  which  is  the  essential  constituent  of  the  majority  of 
pelecypod  forms.  Third,  a  gastropod  shell  is  in  greater 
danger  of  being  crushed  by  the  pressure  of  the  inclosing 
sediments  because  of  lack  of  support  from  within  the  shell. 
The  body  cavity  of  gaping  bivalved  shells  is  almost  of  neces- 
sity filled,  while  the  sediments  are  intruded  less  readily 


90  Upper  Cretaceous  Fauna  from  Tennessee       [288 

through  the  aperture  in  the  spiral  body  cavities  of  univalves. 
The  shells  thus  unsupported  within  become  crushed  by  super- 
incumbent .sediments  and  are  then  rapidly  disintegrated. 

In  general,  the  Tertiary  and  Eecent  faunas  of  North 
America  contain  a  greater  number  of  univalves  species  and 
it  may  be  that  about  the  same  proportion  existed  in  all  the 
Cretaceous  faunas.  Yet  it  may  be  that  the  faunas,  as  they 
have  been  reported,  represent  the  natural  proportions  in 
which  these  animals  lived  in  the  Cretaceous  sea.  It  is  possible 
that  the  gastropods  became  diversified  in  the  Cretaceous  and 
that  this  diversification  took  place  only  in  certain  provinces, 
where  environments  favored  variation.  Excavating  and  ex- 
tensive collecting  in  localities  where  the  shells  are  especially 
well  preserved  will  probably  throw  some  light  on  this  question. 

In  the  order  Opisthobranchiata  there  are  three  families  and 
four  genera  found  in  the  Coon  Creek  collection.  Of  these 
the  family  Acteonidae,  which  had  its  beginning  in  the  Devo- 
nian and  gained  great  prominence  in  the  Mesozoic  is  repre- 
sented by  the  genera  Act  eon  and  Tornatella.  The  former  in- 
cludes probably  five  species  and  the  latter  two.  The  families 
Ringiculidae  and  Scaphandridae  are  each  represented  by  one 
genus  and  one  species. 

The  order  Ctenobranchiata  is  most  abundant  and  is  repre- 
sented by  48  genera,  30  of  which  belong  to  the  suborder 
Toxoglossa  and  18  -to  the  suborder  Streptodonta.  Among 
the  Toxoglossa  the  family  Cancellariidae  is  first  differenti- 
ated in  the  Upper  Cretaceous.  It  appears  suddenly  much 
diversified  in  that  period  and  attains  its  maximum  distribu- 
tion in  the  late  Tertiary  and  Eecent.  This  family  is  repre- 
sented at  Coon  Creek  by  two  genera.  The  most  prolific  of 
these  is  Paladmete,  a  genus  first  recognized  and  described  by 
Dr.  Julia  A.  Gardner  who  has  recently  monographed  the 
Upper  Cretaceous  Mollusca  of  Maryland.16  The  type  spe- 
cies of  Paladmete  is  very  abundant  in  Maryland  and  north- 


16  Gardner,  J.  A.,  Md.  Geol.  Survey,  Upper  Cretaceous  vol.,  Text, 
p.  412,  1916. 


289]  B.  Wade  91 

ern  Mississippi.  The  genus  is  represented  by  three  species  at 
Coon  Creek.  Mataxa  is  a  form  regarded  by  me  as  a  new 
genus  and  is  referred  to  the  Cancellariidae.  A  species  of 
Mataxa  has  been  described  from  South  India  by  Stoliczka 1T 
and  asigned  to  the  genus  Narona  of  the  Cancellariidae.  A 
study  of  Stoliczka's  description  and  figures  together  with 
perfect  specimens  from  Coon  Creek  shows  that  these  species 
belong  to  the  same  genus  which  is  evidently  not  Narona,  so 
it  seems  advisable  to  assign  these  two  forms  to  Mataxa  as  a 
new  genus  in  the  Cancellariidae.  The  Turritidae  is  another 
family  which  is  represented  in  the  Cretaceous  by  several 
forms  and  is  not  found  in  earlier  strata.  There  are  two  gen- 
era of  this  family  at  Coon  Creek,  Turris,  and  Surcula.  The 
latter  is  especially  varied,  and  includes  probably  six  species. 
The  Volutidae  is  the  most  prolific  and  interesting  family 
of  the  Coon  Creek  collection.  It  contains  six  genera  and 
sixteen  species,  nearly  all  of  which  are  represented  by  abun- 
dant, well  characterized  and  perfectly  preserved  shells.  The 
remarkable  efflorescence  of  the  Volutes  in  the  Upper  Creta- 
ceous has  been  discussed  by  Dall  who  mongraphed  the  Volu- 
tidae in  1890  18  and  in  1907.19  The  Coon  Creek  Volutes 
include  the  genera  Volutomorpha,  Volutoderma,  Ptychosyca, 
Liopeplum,  two  new  genera,  Drilluta  and  Tectapl^ca  and  two 
species  of  a  form  whose  generic  relations  have  not  been  fully 
determined.  The  genus  Ptychosyca  was  named  and  described 
by  Gabb  in  1876.20  Dall  did  not  consider  this  genus  a 
Volute  in  his  monograph  of  this  family,  but  two  species  re- 
presented by  well  preserved  material  in  the  McNairy  County 
collection  reveal  new  characters  that  indicate  that  this  form 


17  Stoliczka,  F.,  Geol.  Surv.  of  India,  Cret.  Faunas  of  South  India, 
vol.  ii,  p.  166,  pi.  xiii,  figs.  15,  16. 

18  Dall,  1890,  Trans.  Wagner  Free  Inst.  Sci.,  Philadelphia,  vol.  iii, 
pt.  1,  p.  72. 

19  Dall,  1907,  Smiths.  Misc.  Coll.,  vol.  iv,  pt.  1,  pp.  1-23. 

20  Gabb,  W.  M.,  Proc.  Acad.  Nat.  Sci.,  Philadelphia,  1876,  p.  295, 
pi.  17,  figs.  2-4. 


92  Upper  Cretaceous  Fauna  from  Tennessee       [290 

is  quite  probably  a  member  of  the  Volutidae  and  near  the 
genus  Liopeplum. 

The  Mitridae  and  Vasidae  are  each  represented  by  one 
genus.  The  genus  Xancus  of  the  Vasidae  is  represented  by 
three  species  which  are  well  characterized  by  the  manner  of 
excavation  of  inner  lip  and  number  of  columellar  folds.  This 
genus  is  well  represented  in  the  Upper  Cretaceous  and  was 
first  identified  from  the  Cretaceous  quite  recently  by  Dr. 
Gardner.21  The  Fusidae  which  appeared  in  the  Jurassic  and 
are  widely  developed  in  the  Tertiary  and  Recent  are  repre- 
sented at  Coon  Creek,  besides  the  genus  Fusus,  by  a  form 
which  is  considered  of  the  rank  of  a  subgenus  under  Fusus 
and  given  the  name  Anomalofusus  as  a  new  subgenus.  The 
Fusidae  are  further  represented  by  two  very  common  well 
characterized  species  for  which  the  new  genus  Ornopsis  has 
been  proposed.  The  family  Fasciolariidae  embraces  the  gen- 
era Piestochilus  and  Odontofusus,  the  latter  being  repre- 
sented by  three  species  which  are  very  closely  related.  The 
well-characterized  genus  Sargana,  of  the  Thaisidae,  is  repre- 
sented at  Coon  Creek  by  two  species,  one  of  which  is  very 
abundant  and  perfectly  preserved. 

The  family  Busyconidae  is  interesting  in  that  it  appears 
rather  suddenly  in  the  Cretaceous  with  numerous,  diversified 
representatives.  At  Coon  Creek  it  is  represented  by  three 
genera  and  seven  species.  These  genera  are  Busycon,  Pyrop- 
sis  and  Pyrifusus. 

Pyropsis  and  Pyrifusus  are  very  abundant  in  the  Creta- 
ceous and  have  a  world-wide  distribution.  Busycon,  very 
commonly  known  as  Fulgur,  is  rarely  found  in  the  strict 
sense  in  the  Cretaceous.  This  extension  of  the  range  of  this 
common  East  Coast  Tertiary  and  Recent  form  is  of  particular 
interest.  It  is  represented  in  the  present  Coon  Creek  col- 
lection by  a  single  well  preserved  specimen,  a  description 
of  which  has  been  prepared  for  publication.  This  specimen, 
aside  from  the  absence  of  the  protoconch  is  perfect  and  pre- 


21  Gardner,  J.  A.,  loo.  cit.,  p.  434. 


291]  B.  Wade  93 

sents  generic  characters  which  cannot  be  mistaken.  The 
species  bears  a  striking  resemblance  to  some  of  the  medium- 
sized  late  Tertiary  and  Eecent  species.  All  the  typical  Ful- 
gurs  previously  known  have  been  limited  to  the  Tertiary  and 
Eecent  of  the  Atlantic  States.  The  Eocene  forms  are  small, 
rather  thin-shelled  species,  so  it  has  been  considered  that  the 
genus  evolved  during  that  period.  The  living  Fulgurs  have 
been  very  extensively  studied  and  the  life  history  carefully 
worked  out.  The  limited  geographic  range  has  been  ex- 
plained in  a  large  measure  by  the  fact  that  the  animal  is 
deprived  of  an  active  free-swimming  larval  stage  by  the  loss 
of  the  velum  before  the  young  form  emerges  from  the  egg- 
capsule.  This  same  fact  might  well  be  cited  to  explain  the 
very  limited  distribution  of  Busy  con  in  the  Cretaceous.  One 
of  the  earliest  Tertiary  species  (described  and  referred  to 
genus  Fulgur  by  Harris22),  occurs  in  the  Midway  group  of 
the  Eocene  about  30  miles  west  of  Coon  Creek. 

In  the  family  Buccinidae  there  is  a  species  represented  by 
large  elegant  specimens  which  seems  to  belong  to  a  well- 
defined  generic  group  for  which  the  name  Hydrotribulus  has 
been  proposed.  Species  of  this  genus  have  been  recognized 
from  Brightseat,  Maryland  and  Owl  Creek,  Mississippi.  A 
study  of  the  description  of  a  species,  Tudicla  monheimi 
(Muller)  Holzapfel23  from  the  Aachen  beds  of  western  Ger- 
many shows  that  the  European  form  belongs  to  the  same 
genus  as  the  American  forms  and  it  seems  advisable  to  pro- 
pose a  new  genus  for  this  group.  Hemifusus  is  another 
genus  that  occurs  among  the  Coon  Creek  Buccinidae  and  is 
a  form  which  has  never  before  been  reported  from  the  Cre- 
taceous of  Eastern  United  States. 

In  the  family  Nyctilochidae  there  is  a  single  genus  Tri- 
tonium.  The  family  Columbellariidae  is  represented  by  a 


22  Harris,  G.  D.,  Bull.  Amer.  Pal,  1896,  vol.  i,  no.  4,  p.  96,  pi.  9, 
fig.  13. 

23  Holzapfel,   E.     Pelaeontographica,    1888,    Band   xxxiv,   pag.    106, 
Taf.  xi,  figs.  4-7. 


94  Upper  Cretaceous  Fauna  from  Tennessee       [292 

single  small  individual  which  has  been  assigned  to  the  genus 
Columbellina,  a  group  not  previously  reported  from  the  Cre- 
taceous of  North  America.  One  species  of  the  genus  Pugnel- 
lus  of  the  Strombidae  is  very  common  in  the  Coon  Creek  beds. 
A  species  of  Rimella  of  the  same  family  is  represented  by  one 
specimen.  The  family  Aporrhaidae  is  prolific,  its  two  gen- 
era Aporrhais  and  Anchura  include  probably  nine  species. 

In  the  suborder  Streptodonta  the  families  Scalidae,  Ceri- 
thiidae,  Trichotropidae,  Vermetidae,  and  Turritellidae  are 
each  represented  by  a  single  genus.  In  the  genus  Turritella 
there  are  probably  8  species.  Both  Lunatia  and  Gyrodes  of 
the  Naticidae  are  common.  The  individuals  of  one  species 
of  Lunatia  are  probably  more  abundant  than  any  other  gas- 
tropod species.  The  family  Capulidae  is  represented  by 
small,  fragile  individuals  of  a  single  species  of  the  genus 
Thylacus  which  was  described  from  Owl  Creek  by  Conrad  in 
I860.24  The  individuals  of  this  species  are  small  and  very 
fragile,  yet  they  are  abundant  and  perfectly  preserved  in 
their  natural  habitat.  They  occur  in  place  fitting  snugly  to 
the  columellar  walls  in  the  body  cavities  of  larger  gastropods. 
They  have  the  internal  muscular  impression  produced  and 
leaving  the  wall  of  the  shell  at  the  anterior  extremities,  and 
lack  the  calcareous  foot-plate  characteristic  of  the  genus 
Hipponix  of  this  family.  The  family  Littoriniidae  is  repre- 
sented by  the  genus  Littorina  which  is  common  in  the  Ter- 
tiary and  Eecent  of  the  East  Coast  and  Gulf  regions,  but  up 
to  the  present  has  not  been  reported  from  the  Cretaceous  of 
these  regions.  f- 

The  genus  Leiostraca  of  the  family  Eulimidae  and  order 
Aspidobranchiata  is  represented  by  abundant  but  often  poor- 
ly preserved  specimens,  due  to  the  fragility  of  the  shell. 
The  family  Euomphalidae  which  is  variously  represented  in 
both  the  Paleozoic  and  Mesozoic,  includes  a  new  genus  Hip- 
pocampoides.  This  is  a  much  depressed  form  with  a  pro- 


24  Conrad,  T.  A.,  Jour.  Acad.  Nat.  Sci.,  Philadelphia,  1860,  vol.  iv, 
2d  ser.,  p.  290,  pi.  46,  fig.  22. 


293]  B.  Wade  95 

duced  keel  and  angular  shoulder.  Most  of  the  specimens  in 
this  family  that  have  been  described  from  the  Cretaceous  of 
the  Eastern  United  States  have  been  referred  to  the  genus 
Straparollus,  and  in  most  cases  these  specimens  are  casts 
and  do  not  show  any  shell  characters,  so  that  it  is  possible 
that  some  of  these  casts  belong  to  Hippocafrnpoides.  The 
family  Turbinidae  is  herein  reported  from  the  Cretaceous 
of  Eastern  North  America  for  the  first  time.  This  family 
is  abundantly  developed  in  the  Paleozoic  and  is  common  in 
the  Eecent.  The  new  genus  Schizobasis  which  is  character- 
ized by  a  very  unique,  flattened  notch-like  anterior  canal 
is  referred  after  some  hesitation  to  the  family  Turbinidae. 
The  families  Trochidae  and  Umboniidae  which  have  repre- 
sentatives from  the  Silurian  to  the  Recent  are  each  repre- 
sented by  a  genus  in  the  Coon  Creek  fauna.  These  genera 
are  Solariella  and  Teinostoma  respectively  and  are  both 
herein  reported  for  the  first  time  from  the  Cretaceous  of 
North  America.  Another  genus  hitherto  unknown  in  Ameri- 
can Cretaceous  is  Liotia  of  the  family  Delphinulidae  and  in 
this  family  occurs  another  very  abundant  form  at  Coon  Creek 
for  which  the  genus  Urceolabrum  is  here  proposed.  This 
seems  to  be  a  well  denned  generic  group  near  Liotia  but  dis- 
tinctly different  from  typical  Liotiae  occurring  in  the  same 
strata.  Besides  the  Coon  Creek  species  Urceolabrum  includes 
an  undescribed  species  from  Aufaula,  Alabama,  and  another 
from  the  Aachen  beds  25  of  Vaals,  Germany. 

In  addition  to  the  above  cited  genera  there  are  probably 
as  many  as  thirteen  genera  of  Gastropoda,  including  that 
many  and  more  species  whose  generic  and  .family  relations 
cannot  be  assigned  with  assurance  on  account  of  their  frag- 
mentary character. 

The  point  of  greatest  interest  in  the  Coon  Creek  gastro- 
pods is  the  occurrence  of  eight  new  genera  and  one  new  pub- 
genus,  many  of  which  are  represented  by  more  than  one  spe- 


25  Holzapfel,  E.,  Palaeontographica,  Band  xxxiv,  p.  170,  Taf .  xviii, 
figs.  3-7. 


96  Upper  Cretaceous  Fauna  from  Tennessee       [294 

cies  and  also  from  more  than  one  locality,  as  is  shown  in  the 
literature  by  described  species  which  have  been  questionably 
assigned  generically.  The  genera  Solariella,  Liotia,  Teinos- 
toma,  and  Columbellina  have  not  been  previously  reported 
from  North  American  Cretaceous,  and  Hemifusus  and  Lit- 
torina  have  not  been  previously  reported  from  the  Cretaceous 
of  the  Eastern  United  States.  A  typical  Busycon  or  Fulgur  2G 
is  for  the  first  time  found  in  Cretaceous  sediments.  The 
Volutes  are  profusely  developed,  being  represented  by  six 
genera  and  eighteen  species. 

Among  the  Cephalopods  both  the  nautiloids  and  ammonoid 
orders  are  present  and  represented  by  abundant  large  well- 
preserved  specimens.  It  is  interesting  to  find  the  remains 
of  the  most  primitive  order  of  Cephalopoda  which  ranges 
from  the  Paleozoic  to  the  Eecent  associated  with  abundant 
remains  of  the  most  highly  complex  and  degenerate  cephalo- 
pods,  indicating  that  both  thrived  under  the  same  conditions, 
yet  the  latter  became  extinct  and  the  former  continues  to 
live.  The  family  Nautilidae  is  represented  by  one  species 
of  the  genus  Eutrephocems.  The  most  common  cephalopods 
at  Coon  Creek  are  the  Baculites  and  Turrilites  of  the  family 
Lytoceratidae.  Baculites  is  profusely  developed  and  proba- 
bly includes  three  species.  The  Cosmoceratidae  include  one 
species  of  the  genus  Scaphites. 

Conditions  must  have  been  especially  favorable  for  mollus- 
can  life  in  the  Upper  Cretaceous  sea  in  which  the  members 
of  the  Coon  Creek  assemblage  grew.  A  glance  at  a  tray  of 
specimens  impressed  the  observer-  with  the  fact  that  the  shells 
are  the  remains. of  once-flourishing  animals.  Very  many  of 
the  shells  are  thick,  stout  and  of  imposing  dimensions.  Evi- 
dently they  belonged  to  robust,  healthy  and  well-fed  organ- 
isms. The  bivalve  with  the  greatest  lateral  dimensions  is  a 
species  of  Inoceramus  which  was  probably  15  inches  in  maxi- 
mum diameter.  One  species  of  Cardium  is  5  inches  in  length 


26  Bruce  Wade,  1917,   Am.  Jour.   Sci.,  vol.   xliii,  no.   256,   p.   293, 
figs.  1  and  2. 


295]  B.  Wade  97 


and  a  Cyprimeria  is  4^/2  inches.     Exogyra  costata  and  Gry- 

phaea  vesicularis  occur  in  their  typical  massiveness.     The 

shells   of   Cucullaea,   Crassatellites   and    Veniella   are   very 

abundant  and  evidently  belonged  to  three  very  thrifty  groups 

of  Mollusca  which  lived  under  conditions  especially  suited  to 

the  secreting  of  calcium  carbonate.     The  afflorescence  of  the 

Volutidae  in  the  Upper  Cretaceous  has  already  been  empha- 

sized.   All  the  species  of  this  family  are  above  medium  size 

and  many  of  them  are  very  large.     Perfect   specimens   of 

Volutoderma  in  the  collection  attain  an  altitude  of  half  a 

foot.     There  are  broken  specimens  which  when  perfect  must 

have  been  almost  a  foot  long.    Volutomorpha  is  probably  the 

giant  of  the   Cretaceous  gastropods.     There  is  a  fragmenl 

of  several  whorls  of  the  spire  of  one  species  of  Volutomorpha 

in  the  collection  which  would  probably  be  18  inches  in  length 

were  the  specimen  complete.     The  genus  Ptychosyca  is  large 

and  inornate  while  the  genus  Drilluta  is  elongate  and  elabo- 

rately sculptored.    The  shells  of  Pugnellus  and  Gyrodes  seem 

to   be   relics   of   once   prosperous   organisms   which   saw   no 

hardships  in  life.     Lwpeplum,  Lunatia,  Xancus,  Hydrotri- 

~bulus,  Ornopsis,  etc.,  though  less  in  dimensions  than  some  of 

the  above  forms,  evidently  grew  in  very  favorable  environ- 

ments.    Species  of  such  genera  as  Columbellina,  Solariella, 

Act  eon,  Cerithium,  etc.,  are  much  smaller  in  size,  yet  their 

shells  are  thick  and  stout,  and  no  doubt  grew  where  condi- 

tions were  favorable  for  secreting  calcium  carbonate.     The 

bivalves  also  show  various  ranges  in  size  of  thick,  stout  shells. 

The  Cephalopoda  were  the  largest  of  the  Coon  Creek  Mol- 

lusca.    The  genus  Eutrephoceras  is  abundantly  represented 

by  large  thick-shelled  cavernous  individuals  more  than  six 

inches  in  diameter.    One  species  of  Baculites  is  very  abundant 

and  large.     Although  no  complete,  large  individuals  have  been 

recovered  from  the  matrix,  there  are  several  large  pieces  of 

shells  and  body  chambers  in  the  collection  from   6   to   18 

inches  long  and  restorations  of  these  show  that  some  indi- 

viduals were  five  feet  in  length.    It  should  be  noted  here  that 

while  most  of  the  Upper  Cretaceous  molluscs  had  thick  stout 

7 


98  Upper  Cretaceous  Fauna  from  Tennessee       [296 

shells  with  coarse,  vigorous  ornamentation,  yet  many  pos- 
sessed small,  delicate,  fragile  and.  thin  shells,  but  have  never- 
theless been  preserved  perfectly  to  the  present.  Individuals 
of  species  of  Leda,  Cadulus  and  Teinostoma  are  smaller  than 
a  wheat  gain.  Yoldia,  Anatimya,  Tenea,  Liopistha,  Leio- 
straca  are  represented  by  delicate  and  fragile  individuals. 
One  species  of  Crenella  is  thinner  than  paper  yet  it  is  ele- 
gantly sculptured. 

It  is  impossible  to  postulate  with  assurance  the  depth  of 
the  water  in  which  the  Coon  Creek  fauna  lived.  Such  fami- 
lies as  the  Pernidae,  Volutidae  and  Lytoceratidae,  which  are 
very  prominent  in  the  assemblage,  are  usually  regarded  as 
dwellers  in  the  open  sea  at  a  depth  of  about  50  fathoms. 
Yet  the  Nuculas,  Corbulas,  and  Naticoids,  etc.,  are  for  the 
most  part  dwellers  in  shallow  water  near  shore.  Lobsters 
and  true  crabs  lived  in  great  abundance  in  the  Eipley  sea  as 
is  shown  by  the  remains  of  these  forms  which  are  very  com- 
mon in  the  Coon  Creek  sediments.  There  are  probably  five 
genera  of  the  Eucrustacea,  among  which  is  a  large  crab  about 
seven  inches  across  from  .right  to  left  and  whose  modern 
affinities  live  in  the  intertidal  zone  of  the  seas.  No  fora- 
miniefra  have  been  found.  Only  two  very  small  individuals 
of  two  species  of  corals  have  been  recovered.  These  last  two 
facts,  together  with  the  very  abundant  crab  remains  indicate 
very  near-shore  or  intertidal  waters  as  the  habitat  of  the 
Coon  Creek  fauna. 

As  regards  the  evidence  furnished  by  the  sediments  there 
is  no  well-marked  cross-bedding  which  would  result  from 
strong  current  action.  However,  the  very  presence  of  clastic 
material  such  as  sand  and  clay  require  currents  to  account 
for  transportation,  and  shifting  of  these  currents  to  explain 
the  intermingling  of  these  materials.  The  great  abundance 
of  pelecypods  which  are  organisms  that  feed  for  the  most 
part  on  plankton  is  indicative  of  waters  disturbed  by  cur- 
rents, instead  of  very  calm  seas,  for  plankton  occurs  mostly 
in  water  that  is  agitated  by  currents.  No  pebbles  whatever 
have  been  observed  in  the  sediments  of  the  Coon  Creek 


297] 


B.  Wade 


99 


horizon,  wood  fragments  are,  however,  common.  The  totality 
of  the  evidence  seems  to  indicate  that  the  Coon  Creek  fauna 
lived  in  the  agitated  waters  near  the  coast  of  .a  low-lying 
land  mass. 

A  study  of  the  distribution  and  variation  of  the  faunas 
with  reference  to  the  character  of  the  sediments  in  the  Rip- 
ley  formation  of  northern  Mississippi  and  southern  Tennes- 
see shows  that  the  areas  so  favorable  to  molluscan  life  were 


a  •'.'.*.;.',••'•!  •'..',' •  \ '..'/  .•••'.  '•'..'•  ".•.••'  •'.''..'  •  .  .  '• ..  •  '.•  •  .'  '.  .    •  .' 


W  MUv**y  Group. 

T    Owl  C'rtti    ffcriiiT,  +  N,,tA'rn  fflt* 
17 Mc/fitty  Sin<t    Mimic, 
JHFtiTugin,,**   City  Ho*U°n 

I  Stlmi    CAt2t 


Big  Cut 
S.ln,.r   - 


FIG.  2.     Section  of  Upper  Cretaceous  deposits  of  McNairy  County, 

Tennessee. 

quite  local  in  extent.  The  sediments  bearing  such  an  abun- 
dance of  shells  are  limited  both  laterally  and  vertically  in  the 
Ripley  strata  and  do  not  show  a  uniform  wide  range  over  a 
large  area  as  is  so  commonly  true  of  Paleozoic  fossiliferous 
beds.  (A  diagrammatic  section  SW-NE  across  the  McNairy 
County  is  shown  in  Fig.  2.)  By  tracing  the  Coon  Creek 
horizons  southward  the  plentiful  shells  disappear  leaving  in 
some  places  a  very  dark  non-fossiliferous  clay.  Near  Larton, 
McNairy  County,  the  basal  Ripley  beds  are  represented  by  a 
glauconitic  sand  which  contains  branching  remains  of  the 
so-called  fucoid  Halymenites  major  Lesq.  This  thickness  of 


LOG         Upper  Cretaceous  Fauna,  from  Tennessee       [298 

sand  extends  further  southward  and  at  Sand  Hill  is  over- 
lain by  calcareous  sediments  containing  an  unstudied  fauna 
of  probably  50  species.  Three  miles  farther  southwest  there 
are  non-fossiliferous  gypsifeous  clays  at  the  base  of  the  Eipley. 
Overlying  the  variable  Coon  Creek  horizon  is  a  thickness 
of  ferruginous  and  micaceous  Eipley  clays  which  extends  in 
a  belt  across  the  county.  These  sediments  contain  a  sparse, 
dwarfed  fauna  of  a  few  pelecypod  genera  such  as  Cardium, 
Cyprimeria,  Pecten,  etc.,  none  of  which  are  as  much  as  one- 
half  inch  in  maximum  diameter.  Gastropods,  cephalopods 
and  large  massive  bivalves  such  as  Exogyra  or  Gryphaea  -are 
absent.  Evidently  conditions  were  unfavorable  for  molluscan 
life  where  these  deposits  were  formed.  Above  this  is  the  non- 
fossiliferous  McNairy  sand,  and  overlying  that  is  the  classic 
fossiliferous  Owl  Creek  horizon.  Thus  the  evidence  seems 
to  show  that  there  were  local  areas  where  conditions  were 
very  favorable  for  rapid  development  of  life,  while  other 
regions  were  not  suited  to  the  growth  of  marine  organisms. 
There  were  probably  local  biological  provinces  which  favored 
the  development  of  local  faunas.  This  may  be  observed  in 
a  comparison  of  the  Owl  Creek  and  Coon  Creek  faunas.  Al- 
though these  localities  are  within  sixty  miles  of  one  another 
and  in  the  same  formation,  the  two  faunas  have  a  distinctly 
different  aspect.  Very  many  of  the  species  are  different  yet 
many  are  identical.  There  are  a  number  of  genera  from 
each  locality  not  common  to  the  other.  At  Owl  Creek  the 
percent  of  bivalve  species  is  greater  than  that  of  the  uni- 
valves, while  at  Coon  Creek  the  fauna  is  striking  for  the 
predominance  of  gastropod  species.  The  Cephalopod  SpJie- 
nodiscus  has  not  been  found  at  Coon  Creek  while  at  Owl 
Creek  it  is  represented  by  two  species.  As  has  been  stated 
above  the  Owl  Creek  horizon  is  stratigraphically  above  the 
Coon  Creek  beds  so  there  should  be  some  differences  in  the 
faunas  due  to  age  but  it  is  a  question  whether  there  should 
be  such  a  striking  difference  in  assemblages  from  the  same 
formation  located  so  near  each  other  if  such  conditions  as 
local  biological  provinces  had  not  existed.  It  seems  reason- 


299]  B.  Wade  101 

able  to  conclude  from  a  study  both  of  the  sediments  and  the 
faunas  and  their  distribution  that,  in  this  part  of  the  Mis- 
sissippi Embayment  of  the  Ripley  Sea,  there  were  certain 
restricted  areas,  that  were  especially  favorable  for  the  growth 
of  Mollusca.  These  areas  were  separated  from  one  another 
by  regions,  as  the  sediments  show,  not  so  favorable  for  marine 
life  and  such  regions  as  served  to  hinder  free  migration  from 
one  province  to  another.  In  these  isolated  "  places  of  much 
life"  variations  took  place  due  to  biological  and  physical 
conditions.  Environmental  changes  were  constantly  taking 
place  due  to  shift  and  sinuosity  of  strand-line  and  change 
in  character  of  sediments.  In  many  provinces  the  faunas 
were  destroyed  entirely,  in  places  some  survived  longer  and 
were  dwarfed,  favorable  places  were  crowded  with  great 
hordes  and  here  evolutionary  processes  were  most  active.27 


27  During  the  past  winter,  after  the  above  preliminary  account  of 
the  Coon  Creek  fauna  was  written,  the  writer  has  been  engaged  in  a 
systematic  study  of  the  Gastropoda  of  this  fauna  in  preparation  of  a 
dissertation  to  be  submitted  to  the  Board  of  University  Studies.  A 
few  days  collecting  at  Coon  Creek  during  the  summer  of  1916  added 
many  excellent  and  interesting  specimens  to  the  collection  and 
the  study  of  this  material,  together  with  that  assembled  in  1915,  has 
resulted  in  the  recognition  of  about  75  genera  and  140  species  of 
gastropods  alone.  About  two-thirds  of  these  are  new  species,  as  only 
about  45  species  of  univalves  were  previously  known  from  the  Cre- 
taceous strata  of  the  Eastern  Gulf  Region,  and  of  this  number  only 
about  10  had  been  recognized  in  the  State  of  Tennessee.  It  is  proba- 
ble that  the  locality  is  not  exhausted  as  yet,  and  that  further  col- 
lecting, which  is  planned  for  the  summer  of  1917,  will  yield  a  few 
additional  species  of  Gastropoda. 


102  Tuscaloosa  Formation  [300 


THE   OCCURRENCE   OF  THE  TUSCALOOSA  FORMATION 
AS  FAR  NORTH  AS  KENTUCKY1 

By  BRUCE  WADE 


The  Tuscaloosa  formation  is  the  basal  member  of  the  Upper 
Cretaceous  series  in  the  Eastern  Gulf  Region  of  the  Missis- 
sippi Embayment.  In  Western  Alabama  and  Eastern  Mis- 
sissippi this  formation  consists  of  irregularly  bedded  sands, 
clays,  and  gravels  having  an  estimated  total  thickness  of  1,000 
feet.  In  Professional  Paper  81  of  the  U.  S.  Geological  Sur- 
vey L.  W.  Stephenson  has  readjusted  the  nomenclature  of  the 
Upper  Cretaceous  in  this  region  and  has  defined  the  Tusca- 
loosa with  reference  to  the  other  formations  of  this  series. 
,  Toward  thejntorth  the  Tuscaloosa  deposits  become  much 
•  ,thinnef •"&&&  We- 'made  up  almost  entirely  of  conglomerates 
,w<hjc.h, contain  Httle*sand  and  clay.  Professor  E.  W.  Berry 
hgis;  made  a  'sturdy  brf  this  series  and  has  found  evidence  in  the 
fossil  plants  that  the  clays,  in  the  basal  part  of  the  formation 
in  the  region  of  maximum  thickness,  are  more  ancient  than 
plant-bearing  clays  that  occur  in  the  conglomerates  about 
luka,  in  northeastern  Mississippi  where  the  formation  becomes 
much  thinner.  He  shows  that  an  Upper  Cretaceous  estuary 
existed  for  a  long  time  in  Western  Alabama  before  it  trans- 
gressed into  the  northern  part  of  Mississippi  and  Alabama. 

Until  recently  the  Tuscaloosa  formation  was  thought  to 
thin  out  entirely  in  the  vicinity  of  the  Tennessee-Alabama 
line.  In  1913  H.  D.  Miser  mapped  the  areal  geology  of  the 
Waynesboro  Quadrangle  of  Tennessee  and  found  that  the  Tus- 
caloosa was  150  feet 2  thick  and  extended  over  a  large  part  of 
Wayne  County.  Subsequent  work  by  the  Tennessee  Geologi- 


1  Published  with  the  permission  of  Dr.  A.  H.  Purdue,  State  Geolo- 
gist of  Tennessee. 

2  Miser,  H.  D.,  "  Economic  Geology  of  the  Waynesboro  Quadrangle," 
Resources  of  Tennessee,  1913,  vol.  iv,  no.  3,  p.  107. 


301]  B.  Wade  103 

cal  Survey  showed  that  remnants  of  the  Tuscaloosa  gravel 
occur  in  place  on  the  Highland  Rim  of  Tennessee  as  far 
north  as  the  northern  Lewis  County.3  Farther  north,  during 
the  past  summer,  the  writer  encountered  undescribed  occur- 
rences of  the  Tuscaloosa  formation  which  show  that  the  sedi- 
ments of  this  transgressive  phase  of  the  Upper  Cretaceous 
exist  in  a  chain  of  local  outlying  areas  across  the  State  of 
Tennessee  and  as  far^  north  as  the  ridge  west  of  Canton, 
Kentucky. 

An  important  link  in  this  chain  are  the  gravels  which 
occur  locally  along  the  Nashville,  Chattanooga  and  St.  Louis 
Eailroad  between  McEwen  and  Tennessee  City  and  capping 
the  higher  hills  in  this  part  of  Dickson  County,  Tennessee. 
A  cut  on  the  railroad  about  two  miles  east  of  McEwen  shows, 
resting  on  chert  of  the  St.  Louis  formation,  about  30  feet 
of  very  compact  hard  white  chert  gravel  which  is  very  typical 
of  the  Tuscaloosa  belt  across  the  State.  No  paleontological 
evidence  has  been  obtained  from  the  gravels  about  McEwen 
to  determine  the  age  of  these  deposits,  but  after  a  study  of 
the  lithology  a  swell  as  the  geographic  and  topographic  rela- 
tions, the  Tuscalocsa  age  of  the  McEwen  gravels  can  hardly 
be  doubted.  These  gravels  are  made  up  of  well  rounded  water 
worn  pebbles,  most  of  which  are  one  inch  or  less  in  diameter, 
although  many  are  larger,  often  ranging  up  to  cobbles  six 
inches  in  diameter.  Many  individuals  approach  a  sphere 
in  outline  and  in  this  respect  they  differ  from  the  river 
gravels  which  are  common  in  terraces  along  the  Western 
Tennessee  Valley.  In  the  river  gravels  of  this  region  the 
individuals  are  often  flat,  elongated,  and  subangular.  Small 
discoidal  quartzite  pebbles  are  often  conspicuous  in  the  ter- 
race conglomerates.  The  .Tuscaloosa  conglomerates  consist 
for  the  most  part  of  pebbles  and  boulders  derived  from 
the  Lower  Carboniferous  cherts  which  are  common  in  this 
part  of  the  Mississippi  basin.  Water  worn  sandstone  and 


3  Wade,  Bruce,  "  Geology  of  Perry  County  and  Vicinity."    Resources 
of  Tennessee,  1914,  vol.  iv,  no.  4,  p.  173. 


104  Tuscaloosa  Formation  [302 

iron  oxide  pebbles  have  not  been  observed  in  the  Tusca- 
loosa.  This  is  another  feature  which  serves  to  distinguish 
the  Upper  Cretaceous  gravels  from  the  more  recent  terrace 
gravels  in  this  part  of  the  Embayment  Region,  even  though 
the  latter  may  rest  directly  on  the  former  as  is  frequently  the 
case  in  the  Western  Tennessee  Valley. 

South  of  McEwen,  as  stated  above,  the  isolated  Tuscaloosa 
gravel  areas  may  be  traced  along  the  Highland  Rim  across 
Lewis  County  into  Wayne  and  Hardin  Counties  and  farther 
into  Mississippi  and  Alabama  where, they  are  overlain  by 
marine  Eutaw  deposits  and  consequently  paleontologic  evi- 
dence may  be  obtained. 

The  Tuscaloosa  extends  also  north  of  McEwen.  About  3 
miles  west  of  Canton  in  Trigg  County,  Kentucky,  at  a  point 
just  east  of  where  the  Fulton  and  Nashville  Highway  crosses 
the  divide  between  the  Tennessee  and  Cumberland  Rivers  is 
an  exposure  of  Upper  Cretaceous  which  has  not  heretofore 
been  reported.  The  locality  is  about  7  miles  each  of  the 
Upper  Cretaceous  belt  as  shown  by  the  Geological  Map  of 
Kentucky.4  At  this  locality  the  following  section  may  be 
observed : 

River  Terrace,  sandy  clay  and  leached  soil  which 
becomes  thicker  14  mile  to  the 
west  where  it  contains  thick  beds 
of  ferruginous  conglomerate.  .0  —  12  ft. 

Eutaw,  red  micaceous  sand  containing 
streaks  and  pellets  of  white  clay 
and  remains  of  Halymenites  ma- 
jor Lesquereux 0  —  10%  ft. 

Tuscaloosa,  well  rounded  white  chert  pebbles 
and  cobbles.  The  base  of  the 
Tuscaloosa  was  not  exposed  here 
but  Mississippian  chert  occurs  in 
place  some  distance  below  in  the 
hollow  leading  northward +31  ft. 


4  Sellier,  L.  M.     "  State  Geological  Map."     Kentucky   Geological 
Survey,  1915. 


303] 


B.  Wade 


105 


The  above  section  occurs  in  the  top  of  the  divide  which 
is  probably  more  than  300  feet  above  the  waters  of  the  Ten- 
nessee and  Cumberland  Rivers.  This  divide  is  a  northern 
extension  of  the  Western  Highland  Rim  of  Tennessee  and  it 
is  probable  that  further  study  of  the  plateau  between  the 


FIG.  1. 

Sketch  map  of  the  Eastern  Gulf  area  showing  the  northward 
extension  of  the  Tuscaloosa  formation  from  the  previously  mapped 
area  in  solid  black. 

1. — Section  in  Trigg  County. 

2. — Section  in  Dickson  County. 

3. — Section  in  Lewis  County. 

4. — Section  in  Wayne  County. 

Canton  and  McEwen  localities  will  reveal  isolated  occur- 
rences of  Tuscaloosa  that  form  an  almost  unbroken  chain  of 
the  remnants  of  this  formation  from  Kentucky  across  Ten- 
nessee into  Mississippi  and  Alabama. 

A  study  of  a  map  5  of  the  Upper  Cretaceous  belt  of  the 


6  Stephenson,   L.   W..,   "  Cretaceous   Deposits   of   the   Eastern   Gulf 
Region."    U.  S.  Geological  Survey,  1914,  Professional  Paper  81,  map. 


106  Tuscaloosa  Formation  [304 

Eastern  Gulf  Region  shows  that  the  Tennessee  River  flows 
from  the  east  into  the  Cretaceous  in  northwestern  Alabama 
and  then  takes  a  northerly  course  just  east  of  the  Cretaceous 
across  Tennessee  and  Kentucky.  The  geological  map  shows 
that  the  wide  Tuscaloosa  belt  in  Western  Alabama  and  East- 
ern Mississippi  disappears  entirely  just  north  of  where  the 
Tennessee  River  flows  into  the  belt,  and  in  the  same  part  of 
the  state  the  Eutaw  belt  becomes  abruptly  narrow  and  dis- 
appears long  before  it  reaches  the  northern  limit  of  Tennes- 
see. It  has  been  the  purpose  of  the  present  article  to  call 
attention  to  the  occurrence  of  both  Eutaw  and  Tuscaloosa 
sediments  farther  north  than  has  been  heretofore  reported 
and  to  point  out  that  these  occurrences  show  that  the  Tusca- 
loosa formation,  though  probably  not  as  thick  and  as  wide- 
spread as  in  Western  Alabama  and  Eastern  Mississippi,  was 
at  one  time  an  important  formation  and  covered  large  areas 
in  Tennessee  and  Kentucky,  and  that  the  Eutaw  formation 
extended  farther  east  and  north  of  the  areas  mapped.  The 
erosion  of  the  Western  Tennessee  Valley  has  almost  entirely 
removed  the  Tuscaloosa  deposits  toward  the  north,  and  has 
likewise  removed  a  large  portion  of  the  Eutaw  deposits,  but 
to  a  less  extent  than  in  the  case  of  Tuscaloosa. 

The  accompanying  sketch  map  shows  the  formerly  known 
distribution  of  the  Tuscaloosa  in  Eastern  Mississippi  and 
Western  Alabama  and  the  probable  northward  extension  of 
the  Tuscaloosa  belt  as  shown  by  the  recent  work  in  this 
area. 


305]  G.  E.  Dorsey  107 


THE    HABITAT    OF    BELEMNITELLA    AMERICANA    AND 
MUCRONATA 

By  GEO.  EDWIN  DORSET 


The  question  as  to  whether  or  not  the  almost  cosmopolitan 
range  of  certain  type  fossils  is  an  indication  of  similar  life 
conditions  over  wide  areas,  or  to  what  extent  it  may  indicate 
especially  hardy,  easily  or  rapidly  adaptable  organisms,  has 
never  been  tested.  Presumably  in  the  case  of  some  organ- 
isms cosmopolitanism  is  attained  because  of  the  wide  extent 
of  favorable  environments,  while  in  the  case  of  other  organ- 
isms they  are  less  affected  by  the  environment  or  more 
adaptable  to  it. 

With  the  idea  of  ascertaining  whether  similar  conditions 
of  deposition  of  the  fossiliferous  sediments  as  evidenced  by 
identical  or  similar  lithology  can  be  correlated  with  the 
occurrence  of  particular  species  of  wide-ranging  fossils,  I 
have  taken  the  form  Belemnitella  americana  with  its  Euro- 
pean analogue,  Belemnitella  mucronata,  and  have  searched 
the  literature  .with  regard  to  their  occurrence  and  the  char- 
acter of  the  sediments  in  which  they  are  found.  The  result 
is  very  interesting  and  fairly  conclusive. 

To  anticipate  these  results  I  have  found  that  in  almost 
every  instance  where  these  types  are  found,  they  are  associ- 
ated with  a  lithology  which  indicates  practically  identical 
conditions  of  deposition.  On  the  other  hand,  and  as  a  corol- 
lary to  this  fact,  they  show  no  evidence  of  adaptation.  These 
species  appear  with  unusual  suddenness  and  abundance  to- 
ward the  top  of  the  Tipper  Cretaceous,  spread  rapidly  and 
to  great  distances,  and  die  out  before  the  dawn  of  the  Ter- 
tiary as  abruptly  as  they  appeared.  Throughout  this  com- 
paratively short  period  geologically  they  apparently  main- 
tain a  rigidly  uncompromising  individuality.  However,  the 
fact  that  the  fossil  form  called  Belemnitella  is  merely  a  small 
internal  vestige  of  a  once-enveloping  shell,  and  hence  far 


108         Belemnitella  Americana  and  Mucronata       [306 

from  a  trustworthy  guide  to  the  adaptable  characteristics  of 
the  form,  vitiates  to  a  certain  extent  any  general  conclusions, 
such  as  that  wide-spread  occurrences  of  type  fossils  indicate 
correspondingly  widespread  similarity  of  life  conditions. 
Nevertheless,  the  apparent  inability  of  these  Belemnitellas  to 
live  except  in  a  certain,  rather  fixed  environment,  is  at  least 
suggestive  that  their  powers  of  adaptation  were  limited. 

Whitfield  (1)  describing  the  American  species  writes  as 
follows : 

"  Stylet  or  guard,  rather  large,  solid,  and  heavy,  often  becoming 
thickened  with  age.  Specimens  varying  from  nearly  3  inches  to 
nearly  4  inches  in  length  below  the  base  of  the  slit,  the  larger  ones 
evidently  having  a  length  of  fully  6  inches,  from  the  lower  extremity 
to  the  top  of  the  internal  cavity,  or  conotheca.  General  form  triangu- 
larly cylindrical  in  the  upper  part,  becoming  flattened  on  the  ventral 
side  in  the  lower  part,  with  frequently  a  slight  mucronate  extremity. 
.  .  .  The  upper  end  of  the  stylet  or  guard,  from  about  the  base  of  the 
internal  cavity,  gradually  expands  upward,  and  becomes  very  thin  on 
the  edge,  and  the  inner  surface  of  the  wall  often  bears  the  marks  of 
the  transverse  septa  of  the  phragmacone.  The  entire  surface  is 
usually  much  roughened  When  not  worn,  the  roughening  being  great- 
est on  the  ventral  side,  while  laterally  this  roughening  produces  vas- 
cular lines  running  obliquely  backward,  in  crossing  from  the  ventral 
to  the  dorsal  surfaces,  and  on  the  raised  lanceolate,  area  of  the 
dorsal  surface  the  markings  are  finer  and  arranged  so  as  to  produce 
longitudinal  lines,  or  interrupted  striae." 

There  seems  to  be  a  fair  degree  of  unanimity  as  to  the 
similarity  of  B.  americana  (Morton)  and  the  European  form, 
B.  mucronata,  D'Orbigny.  Morton  says  (2,  p.  190). 

"  This  species  has  an  analogue  in  the  B.  mucronata  of  Schlotheim, 
which  is  characteristic  of  the  Chalk  throughout  Europe.  It  seems 
also  to  resemble  the  belemnite  of  Maestricht,  as  figured  by  Faujas." 

D'Orbigny,  (3,  p.  63-4)  describes  the  European  form  as 
follows: 

"Rostre"  allonge",  quelquefois  un  peu  comprime",  cylindrique  sur  sa 
moitie"  ante"rieure,  de  1&  acumine"  jusqu'a  1'extremite"  tres -obtuse,  au 
milieu  de  laquelle  est  une  pointe  souvent  assez  allonge"e;  les  deux 
impressions  dorsales  sont  tres  marquees,  large,  et  il  en  part  des 
petits  sillons  ramifies  et  reticule's,  qui  viennent  joindre  le  partie  in- 


307]  G.  E.  Dorsey  109 


Scissure  long,  occupant  la  moitie  de  la  cavite".  Cavite" 
ronde,  tres-longue,  conique,  occupant  les  deux  cinquiemes  de  la  lon- 
guer,  pourvues  en  dessus  d'un  sillon  creux  longitudinal;  alveole  avec 
des  cloisons  separges,  dont  les  traces  se  montrent  encore  dans  la 
cavite.  Jeune,  sa  form  est  plus  conique  et  le"gerement  comprime'e." 

Despite  the  fact  that  B.  americana  and  B.  mucronata  are 
regarded  as  type  fossils,  and  that  the  two  forms  are  regarded 
as  closely  related,  they  do  not  represent  exactly  the  sam^ 
horizons  on  both  sides  of  the  Atlantic,  the  American  form 
being  somewhat  older  than  its  European  analogue. 

One  of  the  typical  American  occurrences  is  in  the  Mon- 
mouth  formation  of  the  Upper  Cretaceous  of  New  Jersey. 
J.  A.  Gardner  (4,  p.  396)  says, 

"It  (B.  americana)  is  perhaps  the  most  valuable  horizon  marker 
of  the  Cretaceous,  since  it  has  never  been  reported  from  either  above 
or  below  the  Monmouth,  and  is  determinable  from  the  merest  frag- 
ment." 

The  Monmouth  formation,  whose  type  locality  is  in  Mon- 
mouth County,  New  Jersey,  has  been  divided  by  W.  B.  Clark, 
in  ascending  order,  into  the  Mt.  Laurel  sands,  the  Navesink 
marls,  and  the  Redbank  sands.  The  Belemnitella  zone  in 
New  Jersey  occurs  at  the  Navesink  marl  level  and  thus  is 
about  midway  in  the  Monmouth.  To  the  south,  B.  americana 
is  found  in  the  Peedee  formation  of  North  and  South  Caro- 
lina, and  farther  to  the  south  in  the  Exogyra  costata  zone 
of  the  Selma  Chalk. 

It  apparently  dies  out  before  the  deposition  of  the  upper 
Monmouth.  In  Europe,  B.  mucronata  is  first  found  in  the 
late  Campanian.  It  continues  throughout  the  Maestrichtian, 
that  is  throughout  the  Aturian  or  uppermost  Senonian.  The 
overlying  Danian  from  which  it  is  absent  is  correlated  with  the 
New  Jersey  Rancocas  and  Manasquan  formations.  Thus,  if, 
as  Clark  says  (4,  p.  74),  "The  (Monmouth)  forms  point 
to  the  lower  Senonian  age  of  the  beds,"  then  the  presence  of 
B.  mucronata  in  the  Maestrichtian  is  decidedly  younger, 
particularly  so  since  Belemnitella  is  not  present  in  America 
even  in  late  Monmouth  time. 


110         Belemnitella  Americana  and  Mucronata       [308  • 

The  striking  fact  about  both  the  American  and  European 
occurrences  is  that  B.  americana  and  B.  mucronata  are  prac- 
tically always  found  in  "greensand,"  of  a  very  glauconitic 
nature,  or  in  chalk.  The  explanation  of  this  rather  unex- 
pected uniformity  will  be  discussed  after  a  brief  review  of 
the  occurrences  on  the  two  continents. 

The  marine  Upper  Cretaceous  of  North  America  is  not 
found  farther  north  along  the  Atlantic  coast  than  Long  Is- 
land where,  however,  only  the  earlier  horizons  are  repre- 
sented. M.  L.  Fuller  (5,  p.  77)  says  that  well-borings  are 
sufficiently  numerous  to  make  it  perfectly  clear  that  there 
are,  on  Long  Island,  no  thick  greensand  beds  like  those  in 
New  Jersey,  their  stratigraphic  position  being  occupied  by 
sands.  A  reference  to  his  list  of  Cretaceous  fossils  (p.  78), 
reveals  the  entire  absence  of  B.  americana  from  all  of  these 
beds. 

As  noted  above,  the  Navesink  marls  of  New  Jersey  are  the 
most  northern  occurrence  of  B.  americana.  This  member, 
representing  the  middle  Monmouth  formations  of  New  Jer- 
sey and  Maryland,  embraces  the  Lower  Marl  Bed  of  Cook, 
concerning  which,  W.  B.  Clark  writes  (6,  p.  191):  "The 
lower  Marl  Bed  is  a  characteristic  greensand,  glauconite  en- 
tering to  a  marked  extent  into  its  composition."  The  same 
author  (7,  p.  334)  writes  of  this  formation,  "The  Navesink 
marls  are  typically  glauconitic  sands.  .  .  .  The  basal  por- 
tion consists  generally  of  arenaceous  beds  that  have  been 
hitherto  referred  to  under  the  name  of  sand  marl.  Above 
the  sand  marl  in  the  northern  portion  of  the  area,  is  a  very 
compact  blue  marl,  which  is  highly  glauconitic,  and  fre- 
quently fossiliferous  in  its  central  portions." 

The  Monmouth  formation  reappears  in  Delaware  and  Mary- 
land, where  it  has  lost  the  three-fold  characteristic  of  the 
New  Jersey  section.  As  the  beds  appear  in  northeastern 
Maryland  and  Delaware  they  still  preserve  their  remarkably 
glauconitic  character.  Clark  (4,  p.  70)  says,  "The  Mon- 
mouth formation  consists  chiefly  of  reddish  and  pinkish  sands, 
generally  glauconitic,  the  beds  in  places  forming  a  dark 


309]  G.  E.  Dorsey  111 

greensand."  This  is  true  to  a  marked  extent  for  only  the 
beds  along  Bohemia  Creek  in  Maryland,  in  the  northeastern 
part  of  the  state.  The  Monmouth,  as  it  occurs  on  the  West- 
ern shore  of  the  state,  from  Anne  Arundel  to  Prince  George's 
county,  has  lost  the  markedly  glauconitic  character  of  the 
Bohemia  Creek  facies, — clays  and  muds  being  considerably 
more  prominent.  It  is  especially  significant,  in  view  of  the 
above,  that  we  find  B.  americana  in  abundance  on  the  Eastern 
shore  in  the  glauconite,  and  no  trace  of  it  on  the  Western 
shore  in  the  muds  and  clays. 

Weller  (22,  p.  18)  has  called  attention  to  the  fact  that  the 
Eedbank  sands  of  New  Jersey  pinch  out  passing  to  the  south- 
west, their  stratigraphic  position  being  occupied  by  the  Nave- 
sink  marls  which  here  still  maintain  their  glauconitic  facies. 
Accordingly,  as  one  progresses  toward  Delaware  and  Mary- 
land from  Long  Island,  he  passes  through  a  series  that  is 
progressively  more  glauconitic,  until  over  southwestern  New 
Jersey,  Delaware,  and  northeastern  Maryland  is  located  the 
greatest  development  of  this  facies.  Still  farther  toward  the 
southwest,  the  greensand  aspect  gives  way  to  muds  and  clays, 
until  one  reaches  the  Virginia  land  mass.  This  points  pretty 
definitely  to  the  existence  of  a  basin  in  which  glauconite  was 
being  deposited,  far  enough  removed  from  land,  or  with  such 
a  slight  influx  of  terrigenous  materials,  as  to  give  clear,  quiet 
waters,  during  a  large  part  of  Monmouth  time. 

As  noted  above,  Virginia  was  above  water  during  the  Mon- 
mouth, but  in  North  Carolina,  in  the  so-called  Peedee  sands 
of  Ruffin,  we  have  conditions  of  sedimentation  almost  iden- 
tical with  those  of  the  New  Jersey-Delaware-Maryland  Mon- 
mouth,— a  series  of  alternating  sands  and  clays,  the  sands 
being  highly  glauconitic.  According  to  Stephenson  (8,  p. 
146),  "The  content  of  glauconite  in  the  greensands  of  North 
Carolina  appears  to  be  less  than  that  of  the  greensand  marls 
of  New  Jersey."  A  careful  study  of  the  sections  of  those 
localities  at  which  B.  americana  is  found,  reveals,  without 
exception  the  highly  glauconitic  nature  of  the  fossil-bearing 


112         Belemnitella  Americana  and  Mucronata,       [310 

beds.     A  few  examples  may  be  selected  at  random,  B.  ameri- 
cana  being  recorded  from  each  locality  (8)  : 

U.  S.  GEOLOGICAL  SURVEY,  LOCATION  4133   (p.  153) 
Pleistocene 

Loose,    light    sand 6  ft. 

Unconformity 
Cretaceous    (Peedee  sand) 

Firmly  indurated,  dark  gray,  calcareous,  glauconitic 

sand,   containing  many  fossils 2  ft. 

Dark   green,    argillaceous,    micaceous,    rather    coarse 

sand,   containing  a  few  fossils 7  ft. 

U.  S.  G.  S.  LOCATION  4130     (p.  154) 
Pleistocene 

Loose  white   sand 8  ft. 

Unconformity 
Cretaceous   (Peedee  sand) 

Dark  green,  glauconitic   sand 1  ft. 

Greenish  gray,  glauconitic  and  calcareous  sandstone, 

containing  numerous  fossils l%ft. 

Dark  greenish   gray  glauconitic    sand,   containing   a 

few   fossils    2  ft. 

U.  S.  G.  S.  LOCATIONS  Nos.  4169  AND  4137     (p.  157) 
Pleistocene 

Sand  and  loam  poorly   exposed 15  ft. 

Eocene 

Thin-bedded  shale  with  conglomerate  band  at  base . .       7  ft. 

Unconformity 
Cretaceous   (Peedee  sand) 

Dark  green,   very   compact,   arenaceous,   glauconitic, 
micaceous    clay,    containing    numerous    shells    and 

casts 11  ft. 

Concealed,  to  waters  edge 3  ft. 

The  report  states  that  from  this  locality  the  B.  americana  were 
collected  from  the  greensand. 

This  series  of  sections,  illustrating  the  association  of  green- 
sand  with  the  Belemnitella  remains,  could  be  continued  until 
every  locality  was  listed.  There  are  localities  given,  where,  in 
the  Peedee  greensands,  no  remains  of  Belemnitella  have  been 
recovered.  But  this  can  not  be  regarded  as  evidence  of  any 
kind.  The  fact  that  B.  americana  lived  only  under  conditions 


311]  G.  E.  Dorsey  113 

where  glauconitic  deposition  could  take  place,  does  not  neces- 
sarily imply  that  it  lived  everywhere  where  such  conditions 
existed,  any  more  than  its  isolated  occurrence  in  beds  of 
neither  a  glauconitic  nor  a  chalky  phase  proves  that  the  con- 
stant association  with  such  phases  is 'of  no  significance.  The 
close  proximity  of  the  localities  in  the  Carolinas,  however,  and 
the  evidence  in  favor  of  fairly  widespread  similar  conditions 
during  Peedee  time  point  rather  to  incomplete  fossil  col- 
lections than  to  absence  of  the  form.  ' 

Passing  to  the  south,  and  southwest,  the  horizon  of  the 
Monmouth,  marked  by  greensands  thus  far,  gives  way  to 
chalk.  The  Selma  Chalk,  the  time  equivalent  of  part  of  the 
Eipley,  is  the  next  source  of  B.  americana.  The  greatest 
development  of  the  Selma  Chalk  is  in  central  and  western 
Alabama,  and  in  east-central  Mississippi.  To  the  north  in 
Mississippi  the  Chalk  thins  rapidly  and  becomes  very  argil- 
laceous, and  in  Tennessee  is  a  very  thin  basal  layer  of  the 
Eipley  formation.  An  examination  of  the  tables  of  species 
prepared  by  L.  W.  Stephenson  (9,  facing  p.  24)  reveals  the 
widespread  occurrence  of  B.  americana  in  the  Selma  Chalk. 
Thus  in  east  central  Mississippi  and  adjacent  parts  of  Ala- 
bama, it  is  recorded  from  9  localities;  in  the  region  of  War- 
rior and  Tombigbee  rivers,  Alabama,  from  2  localities;  from 
the  vicinity  of  the  Alabama  Eiver,  Alabama,  from  2  locali- 
ties. About  a  quarter  of  a  mile  east  of  Troy,  Mississippi,  an 
occurrence  of  B.  americana  is  recorded  at  about  the  juncture 
of  the  Selma  and  the  Eipley  (U.  S.  G.  S.  Location  6471) ; 
and  in  the  northern  Mississippi  area  (N.  B.  %  Sec.  14,  T. 
4  S.,  E.  5  E.,  at  U.  S.  G.  S.  Location  544)  the  form  has  been 
recorded  in  the  Eipley  formation ;  and  there  is  no  record  of  its 
occurrence  in  the  Selma  Chalk  proper  in  either  of  these  imme- 
diate regions.  Inasmuch  as  B.  americana  occurs  over  this 
large  area,  practically  everywhere  in  the  Selma  Chalk,  which 
"  consists  in  the  main  of  more  or  less  argillaceous  and  sandy 
limestones,  rendered  chalky  by  their  large  content  of  Fora- 
miniferal  remains,  with  interbedded  layers  of  nearly  pure, 


Belemnitella  Americana  and  Mucronata       [312 

hard  limestones  at  wide  intervals,"  and  as  chalk  has  been 
found  to  be  one  of  the  two  facies  in  which  B.  americana  prac- 
tically always  occurs,  the  various  localities  need  not  be  consid- 
ered in  detail.  In  the  case  of  the  two  Eipley  occurrences, 
however,  the  lithology  must  be  examined. 

Dr.  L.  W.  Stephenson,  of  the  U.  S.  Geological  Survey,  has 
kindly  furnished  me  with  the  following  information  in  regard 
to  these  occurrences.  The  locality  one-quarter  mile  east  of 
Troy,  Mississippi,  came  from  a  "gray,  highly  calcareous 
sandstone,"  of  which  Dr.  Stephenson  sent  me  a  sample.  The 
rock  bears  not  the  slightest  trace  of  glauconitic  material,  but 
is  composed  to  a  very  large  degree  of  limestone,  of  a  chalky 
character.  In  places  the  sand  grains, — milky  quartz, — are 
embedded  in  a  solid  calcareous  matrix.  Thus,  while  not  per- 
haps occurring  in  the  Selma  Chalk  proper,  the  lithology  of 
the  beds  may  be  regarded  as  identical  with  that  of  many 
parts  of  the  Chalk  formation.  Of  location  544,  in  Tippah 
County,  Mississippi,  Dr.  Stephenson  says,  "  the  matrix  at- 
tached to  one  specimen  in  the  lot  is  gray,  calcareous,  glau- 
conitic (  ?)  sand."  This  specimen  is  a  Serpula.  He  does  not 
go  into  further  detail  regarding  the  locality,  but  it  may  be 
a  fair  inference,  despite  a  warning  that  some  of  this  material 
may  be  mixed,  that  glauconite  was  present  at  least  in  the 
vicinity  of  this  occurrence  of  B.  americana.  It  is  rather 
significant  in  this  connection  to  note  that  the  glauconite 
locality  was  in  the  true  Ripley,  at  some  distance  from  the 
Selma  Chalk,  and  the  non-glauconitic,  but  highly  calcareous 
facies,  was  very  near  to  the  contact  of  the  Selma  and  Ripley. 

The  most  noteworthy  gap  in  the  range  of  B.  americana  in 
the  southeastern  United  States  is  in  Georgia.  Here  the 
Eipley  formation  is  well  developed,  attaining  a  maximum 
thickness  of  about  850  feet,  but  nowhere  in  the  large  area 
covered  by  the  formation,  which  at  times  is  somewhat  glau- 
conitic, is  B.  americana  recorded.  The  many  sections  of  the 
Ripley  given  by  Veatch  and  Stephenson  (10),  and  the  nu- 
merous fossil  collections,  never  mention  B.  americana.  This 
is  probably  due  to  the  Georgian  Ripley  being  a  nearer-shore 


313]  G.  E.  Dorsey  115 

deposit  than  the  Selma  or  the  Eipley  to  the  west.  Through- 
out the  Ripley  in  Georgia  are  found  remains  of  plants  and 
lignite,  clearly  pointing  to  an  estuarine  or  very  near-shore 
origin.  On  the  other  hand,  Professor  E.  W.  Berry  has  in- 
formed me  that  to  his  knowledge  there  has  never  been  a 
piece  of  lignite  found  in  the  Chalk.  The  grading  of  the 
Chalk,  to  the  east,  into  sands  and  muds,  is  thus  to  be  taken 
as  indicating  an  approach  to  land,  and  hence  to  compara- 
tively muddy  waters,  which  we  shall  see  were  intolerable  sur- 
roundings for  this  species. 

This  list  of  occurrences  exhausts  the  localities  for  B.  ameri- 
cana.  It  is  restricted  to  the  Atlantic  and  Eastern  Gulf  pro- 
vinces of  the  United  States, — occurring  at  the  Monmouth  or 
Exogyra  costata  level  of  the  Upper  Cretaceous  along  the  At- 
lantic coast  and  in  the  eastern  part  of  the  Mississippi  Embay- 
ment.  The  generalization  that  B.  americana  occurs  mainly  in 
a  chalky  or  a  glauconitic-greensand  facies  will  be  seen  to  hold 
true  to  a  remarkable  extent  throughout  this  range.  Although 
absent  in  many  instances  in  favorable  lithology,  I  have  yet 
to  discover  an  occurrence  in  a  facies  radically  different  from 
the  above. 

The  European  occurrences  of  the  form,  known  as  Belemni- 
tella  mucronata,  D'Orbigny,  conform  in  every  way  to  the  re- 
strictions in  lithologic  characteristics  imposed  by  B.  ameri- 
cana. As  noted  elsewhere,  the  European  horizons  at  which 
B.  mucronata  occurs  are  slightly  younger  than  the  American. 
We  first  observe  its  presence  in  the  uppermost  Campanian, 
but  it  is  the  Maestrichtian  that  witnesses  its  widespread  dis- 
tribution. A  glance  at  a  map  (e.  g.,  Haug,  13,  p.  1299) 
showing  the  distribution  of  the  various  Neocretaceous  de- 
posits will  show  that  the  occurrence  of  chalk  is,  broadly,  in 
a  northwest-southeast  belt,  from  Antrim  in  Ireland,  across 
England,  into  Germany  and  Poland,  and  along  the  eastern 
front  of  the  Carpathian  Mountains,  with  large  areas  in  cen- 
tral and  eastern  Eussia,  and  the  Caucasus  and  Trans-Cau- 
casus. Southwest  from  this  main  basin,  from  Sweden  through 
eastern  France,  is  a  subordinate  trough,  with  a  few  isolated 


116         Belemnitella  Americana  and  Mucronata       [314 

localities  in  west  France,  in  Charente,  these  two  basins  form- 
ing the  legs  of  a  triangle;  and  finally,  eastward  from  the 
southern  limit  of  this  trough,  across  the  present  site  of  the 
Alps,  connecting  the  two  legs  of  the  triangle  is  a  subordinate 
basin,  in  which  marls  and  limestones  were  deposited,  connect- 
ing with  the  basin  of  Eussia. 

This  rough  triangle  around  Germany  left  the  greater  part 
of  the  German  Empire  above  water  during  late  Senonian 
time.  A.  E.  Wallace  (15,  p.  91)  quotes  Sir  Charles  Lyell  as 
follows,  "pure  chalk,  of  nearly  uniform  aspect  and  compo- 
sition is  met  with  in  a  northwest  and  southeast  direction, 
from  the  north  of  Ireland  to  the  Crimea,  a  distance  of  about 
1140  geographical  miles;  and  in  an  opposite  direction  it 
extends  from  the  south  of  Sweden  to  the  south  of  Bordeaux, 
a  distance  of  about  840  geographical  miles."  Wallace  goes 
on  to  say  that,  while  this  marks  the  extreme  limits  within 
which  true  chalk  is  found,  "the  chalk  is  by  no  means  con- 
tinuous. It  probably  implies,  however,  the  existence  across 
central  Europe  of  a  sea  somewhat  larger  than  the  Mediter- 
ranean." 

The  most  widespread  and  the  most  typical  chalks  of  Upper 
Cretaceous  age  are  those  represented  by  the  Upper  Chalk  of 
England,  and  its  equivalents,  the  Campanian  and  Maestricht- 
ian,  of  the  continent.  In  northeastern  Ireland,  in  Antrim, 
under  a  Tertiary  basaltic  flow,  resting  uncomformably  on 
Liassic  and  Ehaetic  strata,  Jukes-Brown  (11,  p.  322)  gives 
the  following  series,  all  of  Upper  Chalk  age: — 

3.  White  limestone,  with  B.  mucronata 100  ft. 

2.  Hard,  pinkish,  glauconitic  limestone,  with  quartz 

grains,  and  phosphatic  nodules 4  ft 

1.  Glauconitic  limestone,  passing  down  into  glauconitic 

sand    16  ft. 

Geikie  (12,  p.  1194)  refers  to  this  series  as  "Hard  white 
chalk,  65  to  200  feet,  with  Echinocorys  [Ananchytes]  sul- 
catus,  etc.  =  Zone  of  B.  mucronata."  Very  little  referable 
to  the  Upper  Chalk  remains  in  Scotland,  but  in  the  west, 
under  the  volcanic  plateaus  of  Mull  and  Morven,  some  of  the 


315]  G.  E.  Dorsey  117 

Upper  Chalk  is  found.  Jukes-Brown  (11,  p.  322)  says  re- 
garding this,  "The  white  sandstones  of  the  west  coast  are 
overlain  by  a  few  feet  of  argillaceous  greensand,  passing  up 
into  glauconitic  limestone,  the  two  being  only  five  to  seven 
feet  thick.  .  .  .  Above  these  is  a  bed  of  white  B.  mucronata 
chalk,  from  three  to  ten  feet  thick,  which  is  evidently  a  mere 
remnant  of  a  much  thicker  deposit." 

In  England,  the  Belemnitella  zone  of  the  Upper  Chalk  has 
been  traced  from  Kent  to  Dorset,  along  the  Channel,  and 
thence  northeastward  to  Norfolk.  It  reaches  a  thickness  of 
100-160  feet  in  the  Hampshire  basin,  and  in  Norfolk  it 
attains  its  maximum  development.  Near  Norwich,  Geikie 
(12,  p.  1193)  describes  it  as  a  "white,  crumbling  chalk,  with 
layers  of  black  flints,  which  have  yielded  abundant  sponge 
spicules."  Everywhere  in  the  British  Isles  where  B.  mu- 
cronata has  been  found,  it  has  been  in  a  pronouncedly  chalky 
matrix. 

On  the  continent,  around  the  eastern  shores  of  the  Baltic, 
the  Senonian  is  present  as  white  cliffs,  in  Pomerania,  in 
Riigen,  along  the  south  shores  of  Sweden,  and  the  Danish 
islands.  It  is  also  present  in  Liinberg  in  east  Prussia.  While 
some  B.  mucronata  are  recorded  in  the  Campanian  (Haug, 
13,  p.  1301),  it  is  first  mentioned  in  this  region  in  the  upper 
Maestrichtian,  in  a  lithology  of  persistent  white  chalk.  Haug 
remarks  in  connection  with  this  occurrence  that  as  in  the 
Paris  Basin,  the  ammonites  are  rare,  and  one  is  certainly 
in  the  presence  of  deposits  of  shallower  seas  than  those  over 
Hannover  and  Westphalia.  Ananchytes  ovatus,  Magas  pu- 
milis,,  and  Terebratula  earned  are  abundantly  associated  with 
the  Belemnitellas. 

Passing  to  the  vicinity  of  the  Anglo-Parisian  Basin,  we 
find  in  the  neighborhood  of  Lille,  and  in  the  province  of 
Hainaut  in  Belgium,  the  Campanian  very  slightly  fossil- 
iferous,  but  the  Maestrichtian  well  represented  by  six  zones, 
according  to  Haug  (13,  p.  1302-3),  in  every  one  of  which 
B.  mucronata  is  recorded.  The  lithology  varies  from  a  phos- 
phatic  conglomerate  at  the  base,  with  broken  remains  of  B. 


118         Belemnitella  Americana  and  Mucronata       [316 

mucronata,  through  chalks  of  varying  degrees  of  purity,  with 
an  occasional  conglomerate  intercalated,  to  the  basal  con- 
glomerate of  the  "tuffeau  de  Ciply,"  which  transgresses  the 
two  upper  zones  of  the  Maestrichtian  proper.  In  the  pro- 
vince of  Limburg,  in  Belgium,  the  Campanian,  though  glau- 
conitic,  has  not  as  yet  yielded  any  Belemnitellas ;  but  the 
Maestrichtian,  here  divided  into  five  zones,  contains  B.  mu- 
cronata  throughout.  It  is  worth  while  looking  at  the  lithol- 
ogy  of  each  of  these  for  a  moment  (13,  p.  1303-4)  : — 

Zone  1 — (oldest)    Glauconitic  chalk  with  B.  mucronata. 

Zone  2 — Pure  white  or  marly  gray  chalk,  without  flints,  with  B. 

mucronata. 
Zone  3 — Thick  white  chalk  with  black  flints,  with  B.  mucronata, 

grading    off   laterally    into   the   Kunraed   limestone, — 

marly,  gray,  very  fossiliferous,  but  no  B.  mucronata. 
Zone  4 — Tuffs,  with  gray  flints,  with  B.  mucronata. 
Zone  5 — Tuffs,  with  numerous  gastropods,  and  a  few  cephalopods, 

among  these  being  B.  mucronata. 

Haug,  referring  to  this  succession  (p.  1304),  says  the 
Maestrichtian  of  Limburg  is  essentially  a  neritic  formation, 
offering  few  or  no  paleontologic  affinities  with  the  bathyal 
type  of  the  stage,  such  as  existed  in  the  northeast  of  Germany. 

In  the  Paris  Basin,  proper,  the  Upper  Senonian  is  divided 
according  to  Grossouvre,  into  the  following : 

Campanian 

Zone  1 — Gray  chalk  of  Hardivillers. 

Zone  2 — Upper  Chalk  of  Reims,  White  Chalk  of  Hardivillers, 

and  Chalk  of  Michery,  with  B.  mucronata. 

Maestrichtian   (craie  de  B.  mucronata)   Chalk  of  Meudon,  of  Mon- 
terau,  and  of   St.  Aignan,  with  B.  mucronata. 

The  fauna  of  the  chalk  of  Meudon  is  very  rich,  but  ammon- 
ites are  rare  in  it,  while  Inoceramus,  Pecten,  Ostrea,  and 
Brachipoda  are  well  represented.  In  the  southern  part  of 
the  Paris  Basin  the  Maestrichtian  is  represented  by  only  its 
lower  beds,  the  time  of  the  typical  Maestrichtian  of  the 
northeast  being  a  period  of  emergence  in  this  region.  In 
Normandy,  however,  the  Maestrichtian  is  the  only  member 


317]  G.  E.  Dorsey  119 

of  the  Senonian  present.  Here  it  is  a  sandy,  chalky  deposit, 
and  contains  great  numbers  of  fossils,  B.  mucronata  among 
them.  This  occurrence  is  very  similar  to  the  Maestrichtian 
of  the  Baltic  provinces  and  Belgium. 

In  the  Aquitanian  region,  conditions  similar  to  those  in 
Touraine  prevailed,  except  that  here  the  Campanian  in  Cha- 
rente  does  not  carry  B.  mucronata  at  all,  and  the  Maestricht- 
ian, divisible  into  three  zones,  is  present  in  its  entirety.  But 
only  in  the  lowest  zone — a  white  limestone,  with  bryozoa, 
oysters,  etc., — is  B.  mucronata  found.  The  upper  two,  con- 
sisting of  ferruginous  sands  and  yellow  limestones  are  proba- 
bly too  littoral  in  character  to  contain  B.  mucronata.  Haug 
calls  the  Charentian- Senonian  neritic.  In  the  south,  in  the 
vicinity  of  Lyons,  the  Senonian, — here  apparently  undifferen- 
tiated — rests  upon  the  Albian,  and  contains  B.  mucronata 
and  Ananchytes  ovatus.  The  matrix  is  a  grayish  white  lime- 
stone. Similarly,  in  the  Alps,  at  Geneva,  in  a  marly,  gray 
limestone,  with  siliceous  beds  of  Foraminifera  in  the  upper 
part,  the  undifferentiated  Senonian  rests  upon  the  Albian, 
and  contains  B.  mucronata,  with  Ananchytes  ovatus,  and 
some  Inocerami.  Both  of  these  occurrences  are  questionably 
referred  to  the  Maestrichtian. 

From  the  region  of  Lake  Geneva,  the  Senonian  deposits 
occur  in  a  narrow  strip  across  the  Alps,  being  especially  well 
studied  in  the  northern  and  eastern  Alpine  regions.  At 
Tolz,  in  Bavaria,  there  is  a  greensand,  containing  sponges, 
gastropods,  and  B.  mucronata.  Between  Bergen  and  Teisen- 
dorf,  in  the  same  region,  are  forms  like  the  neritic  species  of 
the  Maestrichtian  of  Limburg,  in  a  great  thickness  of  marls 
containing  B.  mucronata  near  the  top.  North  of  Salzburg, 
in  western  Austria-Hungary,  the  Senonian,  composed  largely 
of  marls,  contains  B.  mucronata. 

The  "  couches  de  Gosau,"  a  name  applied  to  a  series  of 
conglomeratic  and  marly  beds  south  of  Salzburg,  in  the  pro- 
vince of  Salzburg,  is  divided  into  five  zones,  the  uppermost 
of  which,  the  marly  "couches  de  Merenthal,"  contain  B. 
mucronata  and  are  correlated  with  the  Maestrichtian.  In 


120         Belemnitella  Americana,  and  Mucronata       [318 

the  southern  Alps,  B.  mucronata  occurs  in  a  thick  series  of 
marly  limestones,  with  a  fauna  composed  of  pelycypods  and 
cephalopods,  known  as  "Petage  de  Brenno." 

In  the  East  Russia-Poland-Carpathian  region,  the  chalk 
covers  vast  areas,  and  everywhere  has  the  same  facies  as  that 
of  the  Anglo-Parisian  Basin  and  north  Germany.  Over 
Poland  and  East  Eussia  the  greater  part  of  the  fossils  come 
from  the  Maestrichtian,  which  is  a  typical  chalk.  To  the 
south,  although  the  Maestrichtian  is  present  over  large  areas, 
its  facies  has  so  changed  (to  sands  and  clays)  that  B.  mu- 
cronata is  rarely  present.  When,  however,  we  do  find  it,  the 
accompanying  lithology  is  unchanged.  In  the  Bulgarian  pla- 
teau and  the  Dobrudja,  there  is  a  thick  series  of  Senonian 
age,  whose  upper  part  is  composed  of  white,  porous  lime- 
stones, with  siliceous  lenses,: — in  every  way,  Haug  says,  like 
the  Anglo-Parisian  Maestrichtian,  and  here  we  find  B.  mu- 
cronata. In  the  Crimea,  the  Campanian  and  lower  Maes- 
trichtian are  composed  of  white  chalk,  in  which  B.  mucronata 
is  present.  The  Senonian  of  the  Caucasus  is  usually  a  white 
chalk,  very  similar  to  that  of  the  Anglo-Parisian  basin,  and 
with  B.  mucronata.  Near  Toupiniza,  in  Servia,  an  occur- 
rence of  B.  mucronata  is  mentioned  in  marly  sands,  but  this 
is  very  near  the  region  of  the  Dinaric  Alps,  where  the  chalky 
limestone  facies,  which  is  characteristic  of  the  Maestricht- 
ian in  most  of  eastern  Europe,  is  absent.  The  geology  of 
Croatia,  Dalmatia,  and  Bosnia  is  in  such  an  unknown  con- 
dition, that  exactly  what  is  present  can  not  be  said,  but  no 
record  of  B.  mucronata  was  found. 

Passing  from  the  Balkans,  the  next,  and  last,  occurrence 
of  B.  mucronata  is  in  the  Magishlak  peninsula,  on  the  north- 
east coast  of  the  Caspian  Sea.  Here  the  following  beds  are 
differentiated  (13,  p.  1337)  :— 

Zone  1 — A  white  chalk,  with  Ananchytes  ovatus,  Inoceramus  bal- 
ticus,  Pycnodonta  vesicularis,  Belemnitella  mucro- 
nata. 

Zone  2 — A  marly  and  glauconitic  chalk,  with  Ananchytes  ovatus, 
Magas  pumilis,  Pycnodonta  vesicularis,  Scaphites 
schluteri,  Hamites  roemeri,  B.  mucronata. 


319]  G.  E.  Dorsey 

Zone  3 — Some  limestone,  with  Echinoconus  conicus,  Ananchytes 
ovatus,  Scaphites  constrictus,  Baculites  incurvatus. 

Zone  4 — Some  marly  sands,  with  Ananchytes  sulcatus,  Terelra- 
tula  fallax,  and  faxoensis,  Pycnodonta  vesicularis. 

The  above  is  a  good  example  of  what  is  contairmally  being 
repeated  in  the  recorded  occurrences  of  this  Belemnitella 
form.  Where  there  is  a  chalky  or  a  glauconitic  facies  the 
form  is  present.  When  this  changes  to  anything  else,  it  is 
almost  invariably  absent. 

The  most  prominent  exception  to  this,  as  will  be  seen  from 
the  facies  given  above,  is  the  area  across  the  Alps, — the  basin 
connecting  the  two  main  basins  from  England  to  Kussia  and 
from  Sweden  to  France.  Here  B.  mucronata  occurs  most 
often  in  a  marly  or  marly  limestone  facies.  It  is  likely  that 
most  of  the  surrounding  country  in  the  late  Senonian  was 
peneplained,  which  would  permit  clear  water  in  very  near 
shore  deposits,  and  explain  the  occurrence  of  limestone  with 
marls.  If  B.  mucronata,  ranging  far  and  wide  over  areas  in 
which  chalk  was  being  deposited  were  to  stray  into  this  basin, 
open  to  the  two  regions  of  congenial  habitat,  they  might  either 
pass  through  to  the  far  basin,  or  die  on  the  way.  If  such  a 
condition  had  existed  we  should  expect  to  find  the  form 
exactly  as  we  do  find  it,  erratically  distributed  in  changing 
lithology. 

If  we  pursue  our  search  for  B.  mucronata  farther  to  the 
east,  into  Persia,  Turkestan,  Siberia,  China,  Japan,  Alaska, 
we  everywhere  find  it  absent.  Although  the  Senonian  is 
present  in  much  of  this  area,  there  are  no  occurrences  of  B. 
mucronata  recorded. 

The  Senonian,  as  it  occurs  around  the  western  shores  of  the 
Mediterranean  Sea,  will  afford  a  rather  impressive  illustration 
of  the  way  in  which,  with  a  change  in  the  facies  of  the  beds,  B. 
mucronata  vanishes.  In  Sicily,  and  in  Spain,  the  Senonian 
is  present  as  sands  with  occasional  limy  lenses.  In  Italy  the 
Hippurites  limestone  is  well  developed.  In  Tunis  the  late 
Cretceous  is  represented  by  white  limestones,  alternating  with 
yellow  marls.  In  the  south  of  Tunis  there  is  also  a  very  well 


122         Belemnitella  Americana  and  Mucronata       [320 

known  fauna,  from  a  great  thickness  of  Senonian,  in  which  all 
stages  have  been  differentiated.  In  Morocco  there  is  less 
known  about  the  Senonian,  but  in  all  of  these  occurrences 
B.  mucronata  is  noticeable  only  by  its  absence.  In  Egypt  the 
Campanian  and  Maestrichtian  are  very  well  developed,  the 
latter  becoming  thicker  as  it  passes  southward.  In  the  north, 
it  contains  oysters  and  Exogyra  overwegi;  to  the  south,  where 
the  facies  is  one  of  ferruginous  sands,  and  gypseous  and  salt- 
bearing  clays,  attaining  a  thickness  of  150  meters,  Zittel  has 
recorded  a  very  large  fauna,  with  no  B.  mucronata. 

Such  negative  evidence  could  be  continued  indefinitely, 
always  affording  striking  corroboration  of  the  evidence  af- 
forded by  its  occurrence.  I  do  not  see  how  it  is  possible  to 
escape  the  conclusion  that  there  is  undoubtedly  some  connec- 
tion between  the  conditions  under  which  glauconite  and 
chalk  were  deposited,  and  endurable  life  conditions  for  B. 
mucronata  and  B.  americana.  Also,  the  abruptness  with 
which  they  disappear  when  any  other  facies  occurs  seems 
to  indicate  a  very  restricted  power  of  adaptation.  Does  their 
occurrence  in  glauconitic  sands  and  chalk  indicate  the  maxi- 
mum effort  of  this  limited  power  of  adaptation  under  two  dif 
ferent  conditions  of  life,  or  do  the  glauconite  and  chalk  mean 
practically  identical  conditions  of  deposition?  The  latter,  in 
the  light  of  the  most  recent  interpretation  of  these  facies,  is 
to  be  regarded  as  the  correct  conclusion. 

The  bathymetric  conditions  under  which  chalk  was  laid 
down  have  been  the  source  of  much  speculation,  which  has 
gradually  undergone  a  most  marked  change.  The  venerable 
and  orthodox  idea  is  that  the  chalk  is  a  deposit  formed  in  a 
large  ocean  at  great  depths, — that  it  is  an  abyssal  deposit  com- 
parable to  the  Globigerina-ooze  of  recent  seas.  The  large  pro- 
portion of  Foraminifera  was  regarded  as  proof  of  this.  Cayeux 
(14,  p.  523-4)  give  a  resume  of  the  various  expressions  of 
opinion  on  the  origin  of  chalk,  dating  from  1833  to  the  end  of 
the  nineteenth  century.  Mantell,  in  1833,  and  E.  A.  C. 
Austin  in  1843,  both  postulate  abyssal  conditions.  Good- 
win-Austin in  1858  writes  that  A.  D'Orbigny  and  E.  Forbes 


321]  G.  E.  Dorsey  123 

believe  in  the  deep-sea  origin  of  chalk,  and  he  adds  that 
the  organic  remains  in  the  chalk  were  carried  there  by  cur- 
rents from  regions  of  shallower  water.  In  1863  Hebert 
said  the  chalk  of  the  Paris  Basin  was  formed  at  a  suf- 
ficiently shallow  depth  for  it  to  take  part  in  .a  period  of 
emergence,  being  the  first  hint  that  chalk  might  not  be 
abyssal.  Delesse  was  the  first  to  introduce  warmth  as  one  of 
the  requisites  for  chalk  deposition,  when  he  said,  in  1866, 
that  the  water  of  the  Paris  Basin  was  of  the  same  tempera- 
ture as  that  of  the  Gulf  Stream  today.  Then  followed  in 
order,  W.  Thompson,  Prestwich,  Whitaker,  M.  J.  Murray,  all 
subscribing  to  the  deep-sea  origin.  In  1877  the  first  dis- 
cordant note  was  sounded  by  Gwyn-Jeffreys,  who  declared  the 
molluscs  of  the  chalk  were  shallow  water  and  tropical  forms. 
A.  Geikie,  in  1879,  supported  this  idea.  Sollas  says  the 
sponges  indicate  a  depth  of  100-400  fathoms.  Lambert,  and 
Prestwich  in  a  later  article,  Peron,  Neumayr,  Agassiz,  and 
Jukes-Brown  have  all  held  that  the  chalk  was  formed  in  deep 
waters.  But  the  many  indications  of  emergence  that  have 
been  found  associated  with  the  chalk  throughout  Europe,  and 
the  absence  in  the  main  of  any  organisms  that  can  only  be 
abyssal,  have  caused  most  present-day  geologists  to  abandon 
this  idea.  A.  R.  Wallace  (15,  p.  87,  et  seq.),  in  1880,  dis- 
cusses the  origin  of  chalk  as  follows: 

"  There  seems  very  good  reason  to  believe  that  few,  if  any,  of  the 
rocks  known  to  the  geologists  correspond  exactly  to  the  deposits  now 
forming  at  the  bottom  of  our  great  oceans.  The  white  oceanic  mud, 
or  Grlobigerina-ooze,  found  in  all  of  the  great  oceans  at  depths  vary- 
ing from  250  to  nearly  3,000  fathoms,  and  almost  constantly  in 
depths  under  2,000  fathoms,  has,  however,  been  supposed  to  be  an 
exception,  and  to  correspond  exactly  to  our  white  and  gray  chalk. 
This  view  has  been  adopted  chiefly  on  account  of  the  similarity  of 
the  minute  organisms  found  to  compose  a  considerable  portion  of 
both  deposits,  more  especially  the  pelagic  Foraminifera,  of  which 
several  species  of  Globigerina  appear  to  be  identical  in  the  chalk  and 
the  modern  Atlantic  mud.  .  .  .  Now  as  some  explanation  of  the 
origin  of  chalk  had  long  been  desired  by  geologists,  it  is  not  sur- 
prising that  the  amount  of  resemblance  shown  to  exist  between  it 
and  some  kinds  of  oceanic  mud  should  at  once  have  been  seized  upon, 


124         Belemnitella  Americana  and  Mucronata       [322 

and  the  conclusion  arrived  at  that  chalk  is  a  deep-sea  oceanic  forma- 
tion exactly  analogous  to  that  which  has  been  shown  to  cover  large 
areas  of  the  Atlantic,  Pacific,  and  Southern  oceans. 

"  But  there  are  several  objections  to  this  view  which  seem  fatal  to 
its  acceptance.  In  the  first  place,  no  specimens  of  Globigerina-ooze 
from  the  deep  ocean-bed  yet  examined  agree  even  approximately  with 
chalk  in  chemical  composition,  only  containing  from  44  per  cent,  to 
79  per  cent,  of  carbonate  of  lime,  with  from  5  per  cent,  to  11  per  cent, 
of  silica,  and  from  8  per  cent,  to  33  per  cent,  of  alumina  and  oxide 
of  iron.  Chalk  on  the  other  hand  contains  usually  from  94  per  <;ent. 
to  99  per  cent,  of  carbonate  of  lime,  and  a  very  minute  quantity  of 
alumina  and  silica.  .  .  .  Sir  Charles  Lyell  well  remarks  that  the 
pure  calcareous  mud  produced  by  the  decomposition  of  the  shelly 
coverings  of  mollusca  and  zoophytes  would  be  much  lighter  than 
argillaceous  or  arenaceous  mud,  and  being  thus  transported  to 
greater  distances,  would  be  completely  separated  from  all  impurities 
.  .  .  Mr.  J.  Murray  .  .  .  says  .  .  .  '  The  Globigerina-oozes  which  we 
get  in  shallow  water  resemble  the  chalk  much  more  than  those  in 
deeper  water.'  Mr.  GUvyn- Jeffries,  one  of  our  greatest  authorities  on 
shells,  taking  the  whole  series  of  genera  which  are  found  in  the  chalk 
formations,  seventy-one  in  number,  declares  that  they  are  all  com- 
paratively shallow-water  forms,  many  living  at  depths  not  exceeding 
40-50  fathoms,  while  some  are  confined  to  still  shallower  waters." 

Wallace  discusses  the  occurrences  of  the  chalk  in  the  two 
great  areas,  from  Antrim  to  Crimea,  and  from  Sweden  to 
Bordeaux,  and  says  it  is  absurd  to  suppose  that  these  areas 
were  oceanic  abysses,  since  we  have  good  evidence  for  believ- 
ing there  was  land  in  Germany  and  in  several  of  the  nearby 
regions.  Moreover,  the  frequent  intercalations  of  sandstones 
and  conglomerates,  limestones,  marls,  and  muds,  contain- 
ing many  of  the  same  fossils  as  the  chalk  do  not  add  to  the 
abyssal  theory.  Finally,  he  says,  the  wide-spread  emergence 
at  the  end  of  the  Mesozoic,  evidenced  by  unconformities  which 
point  to  a  Europe  very  similar  in  outline  to  that  of  today, 
would  make  it  extremely  unlikely  that  there  had  been  any 
depths  over  Europe  comparable  to  the  present-day  oceanic 
abysses.  Wallace  of  course  makes  no  mention  of  the  modern 
theories  of  isostatic  equilibrium  which  support  his  theory 
admirably  by  the  doctrine  of  the  permanency  of  oceanic  basins. 
He  reaches  the  conclusion  that  the  chalk  was  a  deposit  laid 


323]  G.  E.  Dorsey  125 

down  under  a  depth  of  water  varying  from  a  few  feet  to  200 
fathoms,  and  does  not  mean  deep-sea  conditions. 

An  argument  favoring  the  warm-water  origin  of  the  chalk 
is  the  result  of  the  work  of  GL  H.  Drew.,  of  the  Carnegie 
Institution,  upon  the  precipitation  of  calcium  carbonate  from 
the  sea-water  by  bacterial  agencies.  He  says  (23,  p.  136), 
"  Denitrifying  bacteria  possess  the  power  of  precipitating 
soluble  calcium  salts  in  the  form  of  calcium  carbonate  from 
sea-water  ....  bacterial  action  may  have  formed  an  im- 
portant part  in  the  formation  of  the  chalk  and  other  lime- 
stones rocks  in  geologic  times."  These  bacilli,  called  "  Bac- 
terium calcis  "  by  Drew,  grew  best  on  or  near  the  surface  in 
water  from  25  to  31.5  degrees  C.,  with  an  average  of  29  de- 
grees; they  will  grow  very  slowly  at  15  degrees  C.;  "but  its 
growth  is  totally  inhibited  at  10  degrees  C."  As  such  tem- 
perature can  only  be  attained  in  tropical  and  sub-tropical 
oceans  today,  it  is  certain  that  the  seas  of  the  chalk  must  have 
been  of  at  least  this  warmth,  if  any  of  the  chalk  is  due  to 
bacterial  precipitation, — a  view  now  very  widely  held. 

Cayeux  (16,  p.  258-9),  says,  referring  to  the  chalk  of  the 
Paris  Basin,  "  La  craie  du  Nord  est  bien  un  depot  terrigene." 
A.  Geikie  agrees  that  it  is  a  shallow  water  deposit.  De  Lap- 
parent  still  inclines  to  the  belief  that  it  is  a  fairly  deep-sea 
accumulation.  Schuchert  (17,  p.  885),  says  the  evidence  that 
chalk  is  a  shallow  water  deposit  is,  (1)  the  kinds  of  fossils 
indicate  shallow  water,  (2)  the  formations  are  accompanied 
by  sands,  (3)  in  closely  adjoining  areas  equivalent  strata 
contain  no  chalk.  He  sums  the  question  up  as  follows:  "It 
is  now  held  that  the  chalks  are  organic  accumulations  made 
in  the  main  by  the  calcareous  skeletons  of  minute  pelagic  or 
bottom-living  plants  and  animals,  in  clear-water  epeiric  or 
shelf  seas,  adjacent  to  low  lands  with  mild  climates/5 

The  most  important  feature  of  this  summary  is  the  clear- 
water  condition  postulated.  Recent  work  on  the  Selma  Chalk 
has  shown  it  to  be  a  deposit  laid  down  in  water  into  which  no 
muds  or  large  amounts  of  sand  were  carried.  The  calcium  car- 
bonate, freed  of  all  other  sediments,  accumulated  in  a  com- 


126         Belemnitella  Americana  and  Mucronata       [324 

paratively  shallow  basin,  very  often  not  more  than  25  fathoms 
in  depth.  So  with  the  great  European  chalk  deposits.  Their 
purity  is  due  rather  to  clear,  shallow- water  conditions, — condi- 
tions which  a  flat,  peneplained  adjoining  land-mass  would  af- 
ford,— than  to  the  clearness  of  abyssal  oceanic  waters.  The 
depth,  or  the  distance  from  shore  at  which  these  conditions 
would  prevail,  would  be  a  function  of  the  height  of  the  land, 
strength  and  direction  of  currents,  mouths  of  rivers,  etc.  This 
would  suggest  about  the  limit  of  the  continental  shelf,  under 
conditions  as  they  exist  today,  but  in  the  Cretaceous  it  is  prob- 
able that  these  existed  at  much  shallower  depths,  for  the 
reasons  given. 

In  the  case  of  the  glauconitic  facies  of  the  American  hori- 
zons, considerably  more  difficulty  is  experienced  in  reaching 
a  definite  idea  as  to  the  conditions  of  deposition,  due  to  the 
lack  of  knowledge  on  the  formation  of  glauconite.  There 
has  been  no  controversy  comparable  to  that  over  the  chalk. 
The  consensus  of  opinion  seems  to  place  the  areas  over  which 
deposition  is  going  on  today  at  about  the  edge  of  the  con- 
tinental shelf,  or  at  slightly  shallower  depths.  Goldman  (4, 
p.  176-82),  has  a  discussion  of  the  glauconite  of  the  Monmouth 
formation  of  Maryland,  but  does  not  state  at  what  depth  it 
was  formed,  although  he  says  it  is  found  at  91  meters  in  the 
North  Atlantic  today  (4,  p.  176).  Sir  John  Murray  says  the 
glauconite,  which  is  usually  found  in  shells  of  Foraminifera 
when  primary,  -is  always  associated  with  terrigenous  material. 
The  admirable  work  of  L.  Cayeux  (14),  discusses  rather  the 
method  of  formation  of  the  mineral  glauconite  than  the  physi- 
cal conditions  under  which  it  was  deposited. 

F.  W.  Clarke  (18,  p.  135),  summarizes  these  as  follows: — 
glauconite  "is  widely  disseminated  upon  the  sea-bottom,  but 
most  abundantly  in  comparatively  shallow  waters,  and  near 
the  mud-line  surrounding  continental  shores,"  that  is,  "just 
beyond  the  limits  of  wave  and  current  action,  or  in  other 
words  where  the  fine  muddy  particles  commence  to  make  up 
a  considerable  portion  of  the  deposits."  This  is  usually  placed 
at  or  about  the  edge  of  the  continental  shelf,  or  from  80  to  100 


325]  G.  E.  Dorsey  127 

fathoms.  Fine  particles  of  mud  are,  of  course,  as  good  indi- 
cations of  clear  water  as  chalk.  There  seems  to  be  a  general 
unanimity  that  quiet  water  is  a  requisite  in  the  deposition  of 
the  glauconite.  Goldman  (4,  p.  178),  in  speaking  of  the 
chemical  reactions  supposed  to  take  place  in  the  formation 
of  glauconite  says,  "but  whatever  the  process,  the  fact  may 
be  accepted  that  in  the  presence  of  abundant  organic  matter 
in  fairly  quiet  waters,  FeS2  is  formed."  De  Lapparent  (19, 
p.  365),  says  it  is  deposited  in  "green  muds  which  form  in 
depths  from  200  to  1300  meters  along  abrupt  coasts,  where 
no  important  rivers  empty  as  is  the  case  along  the  south  coast 
of  Africa  and  the  coast  of  Australia."  Graoau  (20), says  the 
glauconite  is  formed  in  shallow  water,  on  the  continental 
shelf,  and  is  usually  found  as  replacements  in  the  fine  marine 
muds.  Chamberlin  and  Salisbury  (21,  p.  366-68,  Vol.  i), 
remark  that  "  Glauconite  is,  on  the  whole,  most  abundant 
along  the  edges  of  the  continental  shelves,  though  it  is  by  no 
means  universal  in  this  position.  It  is  not  commonly  found 
in  deep  water,  nor  very  near  the  shore,  but  approximately  at 
the  mud  line." 

But  where  clear,  quiet  waters  prevail  for  any  time,  glau- 
conite can  be  deposited,  even  if  the  waters  are  very  shallow. 
Thoulet  has  found  it  in  the  Gulf  of  Lyons  from  water  of  only 
a  few  feet.  Professor  E.  W.  Berry  informs  me  that  he  has 
found  glauconite  in  very  near-shore  deposits  in  the  eastern 
Gulf  region  of  the  United  States.  It  seems  probable,  in  view 
of  the  predominance  of  sands,  that  the  Cretaceous  glauconite 
was  formed  at  shallower  depths  than  that  being  formed  today 
near  the  edge  of  the  continental  shelf. 

We  are  not  concerned  here  with  any  of  the  discussions  of 
the  chemical  origin  of  glauconite.  It  may  be  formed  after 
the  consolidation  of  rocks,  as  Cayeux  has  shown,  and  it  may 
not  be  due  in  any  way  to  organic  agencies.  All  we  are  in- 
terested in  is  that  the  primary  glauconite  of  the  "  greensands  " 
was  deposited,  in  quiet  waters,  predominantly  clear,  sometimes 
of  very  shallow  depth,  sometimes  in  depths  of  several  hundred 
feet. 


128         Belemnitella  Americana  and  Mwronata       [326 

It  will  readily  be  observed  that  such  a  conclusion  is  identi- 
cal with  that  regarding  the  conditions  under  which  the  chalk 
is  thought  to  have  been  laid  down, — warm,,  clear,  quiet  waters, 
from  50  to  2000  feet  deep,  the  depth  varying  with  the  attitude 
of  the  adjacent  land  masses,  currents,  etc.  The  glauconitic 
and  the  chalky  facies  of  the  Upper  Cretaceous  may  be  taken, 
with  a  considerable  degree  of  certainty,  to  indicate  practically 
identical  conditions  of  deposition, — conditions  which,  in  view 
of  the  comparative  rarity  of  wide-spread  similar  deposits  be- 
fore and  since,  were  produced  by  a  rather  exceptional  combi- 
nation of  physical  factors.  In  such  surroundings  B.  americana 
and  B.  mucronata  appeared  and  rapidly  became  extremely  nu- 
merous. Everywhere  in  the  Atlantic  province  they  are  found 
flourishing  while  warm,  quiet,  clear  waters  prevailed.  But 
they  rarely  strayed  far  beyond  the  limits  of  these  surround- 
ings, and  where  they  did  they  quickly  died  out.  Finally,  the 
physical  changes  which  brought  the  Monmouth  and  Maestrich- 
tian  to  a  close,  in  destroying  the  limited  conditions  under 
which  the  forms  could  live,  caused  their  complete  extinction. 

Nothing  dogmatic  can  be  postulated  from  the  study  of  the 
habitat  of  only  one  or  two  species.  Before  any  universal  con- 
clusions can  legitimately  be  drawn  a  very  large  number  of 
forms  must  be  studied  with  extreme  detail  and  exactness. 
The  forms  I  have  used  may  be  exceptional  in  their  limita- 
tions, and  therefore  possibly  not  typical  examples  of  guide 
fossils.  But  the  evidence  afforded  by  the  occurrence  of  Be- 
lemnitella americana  and  Belemnitella  mucronata  undoubtedly 
points  to  the  conclusion  that  the  wide-spread  occurrence  of 
identical  forms, — which  thus  constitute  intercontinental  guide 
fossils, — may  be  due  to  the  wide-spread  occurrence  of  identical 
life  conditions,  rather  than  to  an  especially  hardy,  or  easily 
and  rapidly  adaptable  form. 

BIBLIOGRAPHY 

( 1 )  R.  P.  WHITFIELD,  "  Gasteropoda  and  Cephalopoda  of  the  Rari- 
tan  Clays  and  Greensand  Marls  of  New  Jersey."  1892. 
U.  S.  Geological  Survey,  Monograph  18. 


327]  G.  E.  Dorsey  129 

(2)  S.  G.  MORTON,  "Journal  of  the  Academy  of  Natural  Sciences 

of  Philadelphia."    Vol.  6,  1829. 

(3)  A.  D'OBBIGNY,  "  Pale^ontologie  Francaise, — Terrain  Cretace," 

Tome  1,  Texte,  1840-41. 

(4)  Upper  Cretaceous.    Maryland  Geological  Survey.    1916,  2  vols. 

(5)  M.  L.  FULLEB,  "The  Geology  of  Long  Island."     1914.     U.  S. 

Geol.  Survey.    Prof.  Paper  82. 

(6)  W.  B.  CLARK,  "Annual  Report  of  the  State  Geologist  of  New 

Jersey."     1892. 

(7)  W.  B.  CLABK,  "  Bulletin  of  the  Geological  Society  of  America," 

Vol.  8,  1897. 

(8)  "The  Coastal  Plain  of  North  Carolina."    Vol.  3,  Publications 

of  North  Carolina  Geologic  and  Economic  Survey. 

( 9 )  L.  W.  STEPHENSON,  "  Cretaceous  Deposits  of  the  Eastern  Gulf 

Eegion,  and  Species  of  Exogyra  from  the  Eastern  Gulf 
Region  and  the  Carolinas."  1914.  U.  S.  Geol.  Sur.  Prof. 
Paper  81. 

(10)  0.  VEATCH  and  L.  W.  STEPHENSON,  "Preliminary  Report  on 

the  Geology  of  the  Coastal  Plain  of  Georgia."  1911.  Bul- 
letin 26,  Georgia  Geol.  Sur. 

(11)  A.  J.  JUKES-BROWN,  "  The  Building  of  the  British  Isles."    3d 

Edition.     1911. 

(12)  ARCHIBALD  GEIKIE,  "Textbook  of  Geology."    4th  edition,  1903. 

2  vols. 

(13)  E.  HAUG,  "  Traite1  de  Geologic."    1908-11. 

( 14 )  L.  CAYEUX,  "  Contribution  a  l'6tude  Micrographique  de's  Ter- 

rains Se-dimentaires."    Lille,  1897. 

(15)  A.  R.  WALLACE,  "  Island  Life."     1880. 

(16)  L.   CAYEUX,   "Annales   de   la   Societe   Geologique   du   Nord." 

Vol.  19.     1891. 

(17)  L.  V.  PIBRSON  and  C.  SCHUCHEBT,  "A  Textbook  of  Geology." 

2  vols.     1915. 

(18)  F.  W.  CLABKE,  "Data  of  Geochemistry."     3d  edition.     1916. 

U.  S.  Geol.  Sur.  Bulletin  616. 

(19)  A.  DELAPPABENT,  "Traits  de  Geologic."     5th  edition.     1906. 

(20)  A.  W.  GBABAU,  "Principles  of  Stratigraphy."     1913. 

(21)  T.  C.  CHAMBEBLIN  and  R.  D.  SALISBUBY,  "Geology."     1904. 

3  Vols. 

(22)  STUABT  WELLEB,  "A  Report  on  the  Cretaceous  Paleontology 

of  New  Jersey."     1907. 

( 23 )  G.  HABOLD  DBEW,  "  Report  of  Investigations  on  Marine  Bac- 

teria carried  on  at  Andros  Island,  Bahamas,  British  West 
Indies,  May,  1912."  Yearbook  10,  Carnegie  Institution  of 
Washington,  1912. 


CONTRIBUTIONS  TO 
PLANT  PHYSIOLOGY 


CONTRIBUTIONS  TO 
PLANT   PHYSIOLOGY 

THE  DEPARTMENT  OF  PLANT  PHYSIOLOGY 

By  BURTON  E.  LIVINGSTON 

The  Department  of  Plant  Physiology,  established  in  the 
autumn  of  1909,  has  experienced  a  very  satisfactory  growth 
during  the  seven  and  one-half  years  of  its  existence.  It  en- 
tered the  present  Laboratory  of  Plant  Physiology  as  soon  as 
the  building  was  completed,  in  the  winter  of  1911-12.  The 
laboratory  building  has  been  described,  with  photographs  and 
plans,  in  the  Johns  Hopkins  University  Circular  for  Decem- 
ber, 1916.  The  present  paper  is  offered  as  a  preface  to  the 
following  preliminary  reports  of  plant  physiological  work 
now  in  progress  or  recently  completed,  and  deals  with  two 
topics,  the  general  aims  of  the  department  and  the  nature  of 
the  work  so  far  accomplished  or  in  progress. 

AIMS  OF  THE  DEPARTMENT 

Nature  of  the  Science — Plant  physiology  occupies  a  some- 
what uncommon  position  among  the  natural  sciences,  having 
many  of  the  characteristics  of  a  young  science,  although  it 
is  not  really  such.  Notwithstanding  the  fact  that  people  have 
been  interested  in  the  physiology  of  plants  for  many  genera- 
tions, the  subject  has  hardly  yet  become  generally  regarded 
as  a  separate  science,  and  it  has  usually  been  included  under 
the  general  designation  of  botany.  Animal  physiology,  which 
is,  of  course,  the  corresponding  subdivision  of  zoology,  has 
long  been  considered  as  distinct.  The  simplest  way  to  make 
the  content  of  plant  physiology  clear  to  one  not  acquainted 
with  it  is  to  point  out  that  it  deals  with  plants  in  exactly  the 
same  way  as  animal  physiology  deals  with  animals.  Thus 
it  has  to  do  with  all  the  processes  that  go  on  in  plants,  and 
it  considers  these  processes  just  as  physics  and  chemistry  con- 

331]  133 


134  The  Department  of  Plant  Physiology  [332 

sider  the  processes  that  go  on  in  inanimate  things.  Indeed, 
the  close  relation  between  the  physiology  of  animals  and  that 
of  plants  is  becoming  so  well  appreciated  in  recent  years  that 
a  science  of  general  physiology  (dealing  with  the  physics  and 
chemistry  of  all  living  things)  appears  to  be  rapidly  devel- 
oping. It  is  seldom  possible  to  treat  any  physiological  topic 
adequately  without  reference  to  both  plants  and  animals. 
Some  of  the  topics  dealt  with  in  plant  physiology  may  be 
mentioned  as  examples.  Such  are:  water  requirement;  nu- 
trition by  inorganic  materials;  nutrition  by  organic  ma- 
terials; the  exchange  of  energy  between  the  organism  and 
its  surroundings;  the  chlorophyll  function;  respiration,  with 
and  without  free  oxygen;  enzymes,  activators,  hormones,  and 
the  general  phenomena  of  catalysis;  the  control  of  growth 
and  development,  including  reproduction;  the  physiology  of 
movement  and  its  control,  and  the  physics  and  chemistry  of 
protoplasm. 

The  non-physiological  aspects  of  biology  may  be  grouped 
together  as  morphology,  which  deals  with  the  structures  of 
organisms.  Perhaps  one  of  the  most  noticeable  aspects  of 
physiological  endeavor,  and  one  in  which  it  differs  remark- 
ably from  morphological  study  at  the  present  time,  is  this, 
that  it  has  little  to  do  with  the  general  problem  of  evolu- 
tion and  phylogeny.  Evolutionary  philosophy  has  been 
built  up  largely  from  morphological  observations,  and  it  is 
only  recently  that  it  has  become  possible  to  relate  different 
organisms  to  each  other  with  reference  to  their  physical  and 
chemical  processes.  The  evolution  of  animals  and  plants  has 
never  yet  been  one  of  the  main  topics  of  physiology. 

The  sciences  of  mycology,  bacteriology,  pathology,  ecology, 
etc.,  all  have  their  morphological  and  physiological  aspects, 
and  their  subject-matter  may  be  treated  from  the  stand- 
point of  static  description  or  from  that  of  process  dynamics. 
Thus,  that  branch  of  pathology  which  deals  with  the  identi- 
fication of  parasitic  organisms  is  mainly  morphological  in  its 
point  of  view,  while  the  sciences  of  toxicology  and  immunology 
are  clearly  branches  of  physiology.  It  is  not  without  sig- 
nificance that  many  of  the  characters  by  which  the  bacteria 


333] 


B.  E.  Livingston 


135 


136  The  Department  of  Plant  Physiology  [334 

are  classified  and  identified  are  physiological,  since  the 
processes  induced  by  these  minute  organisms  happen  to  be 
more  easily  observed  than  are  their  structural  differences. 

Application  of  Physiological  Science — Just  as  physics, 
chemistry,  climatology  and  biological  morphology  become 
applied  in  physiology,  so  does  physiology  become  applied  in 
many  other  lines  of  human  activity.  As  with  other  sciences, 
there  are,  in  general,  two  groups  of  applications  that  are  pos- 
sible. First,  there  is  the  general  application  of  physiologi- 
cal knowledge  and  principle  to  the  formation  of  what  has 
been  called  a  "philosophy  of  the  universe."  This  is  perhaps 
its  application  as  "pure  science/5  and  for  this  application 
plant  physiology  is  almost,  if  not  quite,  as  valuable  as  is 
animal  physiology.  Such  application  is  not  usually  called 
an  application  at  all,  not  being  primarily  practical  for  the 
physical  aspects  of  human  life,  in  the  sense  of  "buttering 
bread."  But  there  are  still  men  who  do  not  live  by  bread 
alone,  and  a  commercial  age  has  not  yet  proved  that  a  gen- 
eral appreciation  of  the  relations  of  the  things  about  us  may 
not  be  ultimately  as  valuable  to  the  human  world  as  are 
those  things  which  money  buys  directly.  It  is  in  this  direc- 
tion of  application  that  modern  natural  science  claims  at 
least  an  equality  with  philology,  history  and  the  other 
humanities. 

The  second  group  of  applications  possible  for  physiologi- 
cal science  includes  those  commonly  called  practical,  by  which 
food  and  clothing  and  dwellings  may  become  more  readily 
available  to  human  beings,  and  by  which  human  health  and 
comfort  may  be  enhanced.  Just  as  animal  physiology  finds  its 
most  numerous  applications  of  this  sort  in  the  fields  of  medi- 
cine, surgery,  hygiene,  animal  husbandry,  etc.,  so  plant  physi- 
ology contributes  most  to  human  physical  welfare  in  the 
fields  of  agriculture,  forestry,  fermentation  operations,  bac- 
teriology, etc.  These  applications  are  more  interesting  to 
more  persons  than  are  those  of  the  first  group  and  their 
importance  is  not  to  be  minimized.  Indeed,  the  more  a  sci- 
ence may  be  practically  applicable  the  more  opportunity  it 
may  have  for  becoming  philosophically  applicable.  The  two 


335]  B.  E.  Livingston  137 

kinds  of  application  advance  hand  in  hand,  but  the  great 
majority  of  individuals  may  remain  generally  careless  of  the 
philosophical  kind.  For  the  growth  of  plant  physiology  and 
for  its  best  service  to  the  world,  it  is  clear  that  most  of  its 
devotees  must  give  much  attention  to  the  practical  problems 
of  plant  production  and  plant  culture,  and  such  is  indeed 
the  case. 

Both  groups  of  applications  have  their  philanthropic  or 
altruistic  and  their  personal  or  selfish  aspects,  using  these 
adjectives  in  their  usual  sense.  Thus,  a  world  philosophy  may 
be  cultivated  with  the  conscious  aim  of  advancing  human  de- 
velopment in  general,  or  with  the  aim  of  advancing  certain 
individuals,  groups  or  institutions,  as  by  increased  financial 
income.  Of  course,  the  two  aspects  overlap,  but  the  broadly 
philanthropic  aim  seems  to  have  been  frequently  more  evi- 
dent than  the  other  among  the  great  philosophers  and  re- 
ligionists of  the  past.  We  are  not  told  that  a  Buddha  or  a 
Christ  or  a  Pasteur  has  given  much  attention  to  personal 
financial  income  or  to  the  copyrighting  or  patenting  of  his 
ideas.  Nevertheless,  it  is  quite  possible  for  a  modern  philo- 
sophical scientist  to  give  attention  to  such  personal  things 
without  detracting  from  the  broader  value  of  his  work. 

The  practical  applications  of  a  science  such  as  plant  physi- 
ology may  be  carried  forward  for  either  altruistic  or  personal 
ends.  The  latter  kind  of  activity  is  commonly  called  com- 
mercial. A  plant  physiologist  may  work  for  years  in  per- 
fecting methods  for  the  production  of  better  or  more  abund- 
ant agricultural  crops,  and  his  main  aim  may  be  either  to 
lower  the  cost  of  food  to  the  multitude,  or  to  gain  for  him- 
self fame  or  financial  profit.  The  work  itself  may  be  the 
same  in  both  cases,  and  even  the  publication  of  his  results  and 
conclusions  may  not  be  markedly  different.  However,  as  in 
all  such  personal  activities,  the  results  eventually  become  free 
to  the  world,  and  may  thus  become  just  as  important  in  gen- 
eral human  advancement  as  though  the  work  had  been  planned 
with  that  end  in  view.  Personal  interest  can  usually  withhold 
results  of  this  kind  for  only  a  limited  time;  patents  and  copy- 


138  The  Department  of  Plant  Physiology  [336 

rights  run  their  courses  and  commercial  secrets  are  sooner  or 
later  divulged.  As  has  been  remarked  above,  the  two  points 
of  view  overlap,  an  individual's -motives  are  seldom  or  never 
exclusively  of  the  one  or  of  the  other  kind,  and  they  shift 
from  time  to  time. 

It  has  seemed  desirable  to  give  space  to  the  discussion  just 
presented,  on  account  of  the  long-standing  misapprehension 
that  still  exists  between  the  exponents  of  "pure  science"  and 
those  of  the  arts  and  commercial  applications  of  science.  The 
writer  is  convinced  that  all  these  various  human  motives  for 
scientific  work  must  exist  side  by  side,  even  in  the  same  indi- 
vidual, and  that  it  is  for  a  university  department  to  present 
all  of  them  to  its  students.  But  the  outstanding  fact  seems  to 
be  that  the  work  itself  should  be  much  the  same  in  all  cases, 
assuming  of  course,  that  actual  dishonesty  is  ultimately  as  bad 
from  the  commercial  point  of  view  as  it  is  from  the  altruistic, 
as  bad  in  practical  applications  to  human  physical  needs  as  it 
is  in  philosophical  applications  to  what  have  been  called 
human  spiritual  needs. 

Training  of  Physiological  Students — It  should  be  appre- 
ciated that  physiology  articulates  intimately  both  with  bio- 
logical morphology  and  with  the  physical  sciences.  It  is 
obvious  enough  that  the  processes  and  reactions  of  living 
things  are  not  to  be  understood  without  a  certain  amount  of 
morphological  or  anatomical  knowledge.  Thus,  anatomy  and 
histology  are,  in  this  way  at  least,  and  otherwise  to  some  ex- 
tent, prerequisite  to  the  study  of  physiology. 

On  the  other  hand,  the  changes  of  matter  and  energy  that 
go  on  in  living  things  cannot  be  seriously  studied  without  a 
broad  and  rather  detailed  knowledge  of  the  principles  ac- 
cording to  which  such  changes  occur  in  dead  matter.  In  this 
way  the  field  of  physiology  furnishes  opportunity  for  the 
application  of  physics  and  chemistry  in  the  understanding  of 
life.  So  important  is  this  consideration  that  physiology  may 
be  defined  as  the  physics  and  chemistry  of  living  things.  This 
consideration  has  not  been  so  generally  appreciated  as  seems 
desirable,  and  many  of  the  present  leaders  in  physiology  have 


337]  ,       B.  E.  Livingston  139 

first  approached  the  subject  through  the  avenues  of  mor- 
phological study.  Perhaps  it  is  because  of  this  that  begin- 
ners are  often  led  to  devote  several  years  to  academic  work 
in  morphological  pursuits  before  they  are  allowed  to  be- 
come acquainted  with  the  physiological  aspect  of  biology,  so 
that  they  discover  the  need  of  an  intimate  knowledge  of 
physics  and  chemistry  only  at  a  rather  late  stage  in  their  de- 
velopment. It  is  a  significant  fact  that  very  few  of  the  present 
workers  in  plant  physiology  have  been  led  to  their  interest 
in  the  subject  from  an  introductory  study  of  the  physical 
sciences,  although  physiology  offers  some  of  the  most  im- 
portant physical  and  chemical  problems. 

Considering  the  general  applicability  of  physical  as  well  as 
morphological  knowledge  to  physiological  study,  it  is  becom- 
ing more  and  more  evident  that  a  tyro  in  physiology  should 
be  encouraged  to  devote  much  more  attention  to  physics  and 
chemistry,  in  the  earlier  years  of  his  preparation,  than  is  now 
generally  the  case — which  necessarily  means  that  he  should 
not  be  encouraged  to  devote  so  much  time  to  biological  mor- 
phology as  he  does  in  most  institutions  where  young  natural 
scientists  receive  their  training. 

The  considerations  just  set  forth  have  been  given  promi- 
nence in  planning  the  training  leading  to  the  doctorate  from 
this  department,  and,  while  no  formal  prerequisites  are  stated, 
the  need  of  as  much  knowledge  of  chemistry  and  physics 
as  the  student  can  obtain  is  constantly  emphasized.  At  the 
same  time  he  is  urged  to  become  well  acquainted  with  the 
main  facts  and  general  principles  of  animal  physiology  and 
with  those  of  the  comparative  anatomy  and  histology  of 
plants,  as  thus  far  available.  Since  climatic  conditions  exert 
such  controlling  influences  upon  the  behavior  of  plants,  that 
physical  branch  which  is  termed  climatology  must  also  re- 
ceive much  emphasis. 

It  is  the  general  plan  of  the  department  to  erect  no  arti- 
ficial barriers  before  the  prospective  student;  the  work  is  so 
organized  that  any  person  who  understands  elementary  phys- 


140  The  Department  of  Plant  Physiology  [338 

ics  and  chemistry  can  enter  our  physiological  work.  If  his 
morphological  or  physical  knowledge  is  inadequate  this  may 
be  corrected  as  his  work  goes  on.  In  short,  an  interest  in, 
and  a  serious  desire  to  become  proficient  in,  plant  physiology 
are  the  only  prerequisites  for  the  training  that  is  here  offered. 

The  work  of  this  department  has  thus  far  been  exclusively 
graduate  work,  so  that  all  of  our  students  are  intellectually 
rather  mature.  The  scarcity  of  opportunities  for  carrying  on 
advanced  work  in  plant  physiology,  together  with  the  fact  that 
numerous  educational  institutions  offer  opportunity  for  ele- 
mentary academic  courses  in  this  and  the  related  subjects, 
have  made  it  appear  undesirable  to  institute  undergraduate 
courses  here.  Experience  seems  to  show,  furthermore,  that 
the  intellectual  power  of  graduate  students  is  greater  among 
those  who  have  migrated  from  one  institution  to  another,  than 
it  is  among  those  who  have  performed  their  undergraduate 
work  in  the  same  institution  as  that  in  which  graduate  work 
is  undertaken.  Whether  a  causal  relation  is  mainly  involved 
here  is  questionable,  for  the  very  fact  of  student  migration 
generally  bespeaks  a  serious  purpose  and  a  definite  aim;  but 
it  is  also  undoubtedly  true  that  student  migration  tends 
strongly  to  prevent  and  to  obliterate  provincial  traits  of  men- 
tal character,  and  to  give  to  the  student  who  has  thus 
migrated  one  or  more  times  a  more  extensive  series  of  in- 
terests and  a  deeper  appreciation  of  relative  values. 

The  general  purpose  in  the  training  of  our  students  may 
be  expressed  as  the  inculcation  of  scholarly  habits  and  of 
personal  judgment  in  the  carrying  out  of  research.  To  this 
end,  the  work  of  the  department  is  carried  on  as  though 
research  itself — productive  scientific  study — were  the  main 
aim.  The  student  thus  becomes,  as  it  were,  an  apprentice  in 
what  is  planned  to  be  creative  physiological  endeavor,  and  he 
develops  through  striving  to  solve  physiological  problems 
and  to  interpret  and  present  the  results  obtained.  He  is 
thus  led  to  read  the  literature  because  he  seeks  the  knowl- 
edge that  it  contains,  rather  than  because  such  reading  has 


339]  B.  E.  Livingston  141 

been  assigned  or  prescribed.  He  also  learns  that  the  plan- 
ning and  the  interpretation  of  experimental  work  require  far 
more  serious  attention  than  does  the  work  itself,  for  a  poorly 
planned  or  poorly  interpreted  piece  of  work  can  result  in  but 
mediocre  results.  The  actual  operations  of  experimenta- 
tion may  be  best  learned  by  carrying  out  a  well  made  plan, 
and  the  interpretation  and  presentation  of  the  results  ob- 
tained determine  for  the  most  part  how  valuable  they  shall 
be  in  the  development  of  the  science.  Thus  as  much  em- 
phasis is  placed  upon  clear  imagination,,  clear  thinking,  and 
clear  presentation,  as  upon  the  many  details  of  the  manipu- 
lation of  apparatus,  so  frequently  considered  as  constitu- 
ting scientific  knowledge.  This  department  does  not  aim  to 
teach  the  subject,  but  it  carries  out  investigations  and  tries 
to  help  the  workers  to  become  independent  in  the  planning, 
prosecution,  and  interpretation  of  research. 

A  single  course  of  semi-formal  lectures,  lasting  through  the 
year,  with  prescribed  laboratory  experiments,  suffices  to  bring 
the  students  into  contact  with  the  various  phases  of  the  sub- 
ject, and  instruction  is  thereafter  mainly  personal,  in  the 
form  of  conferences  upon  the  numerous  matters  that  arise  in 
the  prosecution  of  research.  No  attempt  is  made  to  stand- 
ardize the  students  beyond  the  elementary  phases  of  the 
subject,  but  each  one  is  encouraged  to  develop  along  line? 
determined  by  its  own  natural  bent.  Consequently,  problems 
for  research  are  not  generally  "assigned/'  as  the  phrase  goes 
in  many  university  laboratories,  but  the  prospective  investi- 
gator is  led  and  assisted  to  choose  a  problem  according  to  his 
own  earlier  training  and  present  interest  and  enthusiasm.  An 
attempt  is  made,  however,  to  discourage  the  taking  up  of 
any  problem  that  does  not  promise  results  of  a  definite  nature 
which,  when  they  are  obtained  and  interpreted,  will  surely 
fit  into  the  general  structure  of  plant  physiology. 

It  appears  probable  that  the  majority  of  our  students  will 
eventually  enter  the  field  of  practically  applied  physiology, 
as  investigators  in  agricultural  or  forestry  experiment  sta- 
tions, or  in  commercial  establishments;  but  our  point  of 


142          The  Department  of  Plant  Physiology  [340 

view  is  always  that  of  the  pursuit  of  the  science  for  its  own 
sake,  so  that  as  many  as  may  be  needed  may  find  places  as 
teachers  of  the  subject.  For  all  these  lines  of  endeavor  the 
same  general  kind  of  training  appears  to  be  requisite,  as  has 
been  pointed  out.  Such  training  must  aim  to  make  the  stu- 
dent familiar  with  the  great  principles  of  the  science,  with 
some  of  the  methods  employed,  and  with  enough  of  the  lit- 
erature so  that  he  may  make  efficient  use  of  the  libraries  in 
his  future  work.  Above  all,  he  must  be  led  to  a  facile  and 
versatile  attitude  of  mind,  which  regards  his  science  as  a  con- 
tinuously changing  thing,  with  new  needs  arising  at  every 
turn  of  its  progress;  also,  he  must  be  not  over-timid  in  fol- 
lowing his  problem  wherever  it  may  lead,  even  into  the  fields 
of  other  sciences. 

THE  WORK  so  FAR  ACCOMPLISHED  OR  IN  PROGRESS 

The  accomplishment  of  a  scientific  research  laboratory 
should  be  calculated  as  the  sum  of  two  different  terms.  The 
first  of  these  is,  obviously,  the  progress  actually  made  in  in- 
vestigation, in  the  solving  of  problems,  and  in  contributions 
toward  what  we  name  the  general  fund  of  human  knowledge. 
The  component  parts  of  this  term  are  usually  easy  of  descrip- 
tive statement,  but  difficult  of  comparative  evaluation.  The 
second  term  includes  what  is  commonly  thought  of  in  uni- 
versities as  the  training  of  students,  but  it  should  also  in- 
clude the  intellectual  progress  of  the  laboratory  staff  itself 
(which  ought  to  accumulate  to  form  an  asset  of  some  value) 
and  likewise  the  aid  and  encouragement  furnished  by  the 
laboratory  to  persons  not  directly  connected  with  it  at  all. 
This  term,  as  is  readily  seen,  is  the  educational  one,  and  its 
components  are  very  difficult  both  of  precise  description  and  of 
comparative  evaluation.  Looked  at  in  one  way,  it  may  be  said 
that  the  first  term  measures  the  actual  product  of  the  labora- 
tory as  an  institution  for  the  making  of  knowledge,  while  the 
second  measures  the  preparations  made  for  the  accomplish- 
ment of  future  work  of  many  kinds,  whether  in  research  or 


341]  B.  E.  Livingston  143 

other  lines  of  human  activity.  Both  these  kinds  of  effort  pro- 
gress side  by  side  in  the  life  of  every  individual  and  of  every 
institution;  each  day  is  partly  devoted  to  actual  accomplish- 
ment and  partly  to  preparing  for  future  accomplishments,  and 
the  two  sorts  of  activity  cannot  be  clearly  separated.  Espe- 
cially is  this  true  when  it  is  appreciated  that  the  accomplish- 
ment of  one  worker  becomes  preparation  for  the  future  activi- 
ties of  others,  as  well  as  of  the  same  worker.  These  two  as- 
pects of  our  work  may  nevertheless  be  considered  separately. 

Educational  and  Preparatory. — Considering  the  period 
from  October.,  1909,  to  June,  1917,  38  persons,  including  the 
two  members  of  the  staff  of  the  department,  have  made  use 
of  the  laboratory  of  plant  physiology.  The  periods  of  use 
were :  One  year  for  24  persons,  two  years  for  7  persons,  three 
years  for  5  persons,  four  years  for  1  person,  and  eight  years 
for  1  person.  Thus,  the  laboratory  has  furnished  facilities 
for  mental  development,  roughly  equivalent  to  those  for  65 
persons  for  a  single  year,  or  for  an  average  of  8  persons  per 
year.  Ten  of  the  65  academic  years  considered  are  those  of 
the  professor  (8)  and  instructor  (2). 

Of  the  38  individuals  who  have  used  the  laboratory,  four 
have  worked  here  after  the  attainment  of  the  doctor's  degree 
elsewhere  (two  of  these  are  on  the  staff),  four  have  attained 
the  Ph.D.  degree  from  this  university,  with  Plant  Physi- 
ology as  principal  subject,  and  five  others  plan  to  come  up 
for  the  degree  in  June,  1917,  with  this  as  their  principal  sub- 
ject. Plant  Physiology  has  been  selected  as  a  subordinate 
subject  (in  the  requirement  for  the  Ph.  D.  degree)  by  15  per- 
sons. 

Of  the  four  persons  who  have  received  the  doctor's  degree 
from  this  university,  with  their  main  work  in  this  laboratory, 
one  is  now  employed  in  the  U.  S.  Department  of  Agricul- 
ture, two  in  state  agricultural  experiment  stations,  and  one 
is  on  the  staff  of  the  University  of  the  Philippines.  Thus, 
three  of  these  have  entered  applied  research  and  one  is  de- 
voting a  portion  of  his  time  to  teaching. 


144  The  Department  of  Plant  Physiology  [342 

The  investigation  carried  on  here  has  itself  been  largely 
preparatory  for  future  work;  the  problems  that  we  have  de- 
sired to  attack  could  not  be  undertaken  until  the  field  (which 
is  a  new  one)  had  been  specially  prepared,  so  that  our  con- 
tributions to  the  science  are  to  be  regarded  largely  as  begin- 
nings and  preparations.  It  appears  likely  that  many  of  these 
lines  of  work  will  be  carried  out  elsewhere,  either  by  students 
of  this  university  or  by  others  who  become  interested  as  the 
field  is  opened.  The  general  nature  of  our  problems  will  be 
touched  upon  in  the  following  section. 

One  other  feature  of  the  educational  and  preparatory  work 
carried  on  by  this  department  deserves  mention,  a  feature 
that  may  be  fully  as  important  as  is  the  direct  training  of 
students.  This  laboratory  has  furnished  information  and  ad- 
vice to  many  persons  not  directly  connected  with  it  regard- 
ing problems  bearing  on  the  water  relations  of  plants,  and 
has  thus  been  able  to  render  more  or  less  valuable  aid  to  stu- 
dents in  other  institutions  and  investigators  in  experiment 
stations,  etc.  To  a  lesser  degree  we  have  been  called  upon  to 
aid  outside  investigators  in  other  fields  of  plant  physiology. 
It  has  been  the  practice  of  the  department  to  furnish  ideas 
and  suggestions  quite  freely  to  all  inquirers,  a  practice  in- 
volving the  writing  of  explicit  and  detailed  letters,  but  one 
which  seems  to  be  fully  as  legitimate  and  valuable  as  are  the 
consultations  with  our  own  students  in  residence.  It  is  in- 
tended that  no  such  inquiries  from  outside  the  depart- 
ment shall  be  subject  to  neglect  or  perfunctory  reply;  such 
information  and  suggestions  as  we  have  are  furnished 
promptly  and  freely  to  all  who  ask.  This  makes  the  hand- 
ling of  the  correspondence  of  the  department  a  somewhat 
serious  undertaking,  but  one  that  is  fully  worthy  of  the  time 
and  energy  so  expended.  The  number  of  persons,  in  many 
regions  of  the  world,  who  are  thus  more  or  less  indirectly 
connected  with  this  laboratory,  is  much  larger  than  the 
number  of  workers  who  have  actually  been  in  residence  here. 
Also,  the  director  of  this  laboratory  devotes  considerable  time 


343]  B.  E.  Livingston  145 

to  the  editing  of  plant  physiological  papers  prepared  by  work- 
ers in  other  institutions,  especially  for  Physiological  Re- 
searches, a  series  of  publications  with  which  the  University 
has  no  official  connection  and  for  which  it  furnishes  no  finan- 
cial assistance.  An  English  translation  of  Palladia's  Plant 
Physiology,  with  editorial  additions,  is  about  to  be  pub- 
lished from  this  department.  It  has  been  prepared  from  the 
German  translation  of  the  Sixth  Eussian  edition,  with  incor- 
poration of  the  main  alterations  occurring  in  the  Seventh 
Eussian  edition. 

Contributions  to  the  Science,  and  Researches  Now  in  Prog- 
ress.— To  give  a  clear  idea  of  the  nature  of  the  investigations 
attempted  in  this  department,  it  is  desirable  to  present  a 
brief  discussion  of  the  general  field  in  which  these  investiga- 
tions lie.  The  science  of  plant  physiology  deals  with  the  pro- 
cesses or  changes  that  go  on  in  living  plants.  Now,  to  un- 
derstand a  change  as  fully  as  possible  it  is  required  to  know 
the  change  first  in  a  roughly  descriptive  sort  of  way,  after 
which  our  knowledge  is  to  be  advanced  by  consideration  of  the 
dynamic  and  causal  aspects  of  the  process  considered.  De- 
scriptive physiology  involves  statements  of  the  various  sorts 
of  processes  going  on  in  the  organism,  and  it  should  show  in 
what  regions  of  the  body  these  changes  occur,  and  when  they 
occur.  Thus,  that  ordinary  green  leaves  take  up  the  element 
carbon  out  of  the  air  during  periods  of  sunlight  is  a  state- 
ment of  descriptive  physiology,  in  this  sense.  To  inquire 
more  deeply  concerning  this  process  of  carbon-intake  clearly 
leads  to  quantitive  studies  of  the  various  rates  at  which  this 
intake  may  go  on,  which  may  be  correlated  with  the  various 
concomitant  conditions  of  the  plant  and  of  its  surroundings. 
Such  studies  soon  reveal  the  fact  that  the  rate  of  carbon- 
absorption  is  determined  by  a  host  of  conditions,  each  one  of 
which  requires  to  be  measured  with  regard  to  its  intensity, 
and  it  is  found  that  the  rate  in  question  may  assume  different 
magnitudes  as  the  conditional  intensities  vary.  It  is  true 
that  the  process  of  carbon-entrance  from  the  air  usually 

10 


146  The  Department  of  Plant  Physiology  [344 

ceases,  and  is  replaced  by  one  of  carbon-exit,  when  light  is 
absent,  but  the  same  alteration  may  be  induced  by  many  other 
changes  in  the  surroundings ;  for  example,  by  sufficiently  high 
or  low  temperature,  by  sufficiently  low  water-content  of  the 
leaves,  by  a  sufficiently  high  concentration  of  a  poisonous  gas 
in  the  air,  etc.  It  soon  becomes  clear  that  no  physiological 
process  is  to  be  regarded  as  at  all  well  understood  without  a 
considerable  knowledge  of  its  quantitative  control,  and  dyna- 
mic physiology  deals  with  the  more  elaborate  and  quantita- 
tive statement  of  the  physiological  changes  thus  suggested. 
It  relates  them  to  their  determining  conditions  within  and 
without  the  organism. 

From  the  work  of  earlier  students  many  plant  processes  are 
now  fairly  well  known  in  the  simple,  descriptive  way,  but  none 
of  these  is  yet  at  all  well  understood  in  the  dynamic  or  etio- 
logical  sense.  This  latter  is  the  phase  of  physiology  which  is 
now  beginning  to  attract  the  most  serious  attention,  and  to  it 
will  be  devoted  the  energies  of  investigators  for  many  genera- 
tions to  come.  It  is  to  this  field  of  dynamic  physiology  that 
the  researches  .of  this  laboratory  are  planned  to  apply. 

While  descriptive  physiology,  as  above  defined,  is  a  compar- 
atively old  science,  dynamic  physiology  is  a  young  one,  and 
the  problems  of  the  latter  are  complicated  in  the  extreme — 
there  are  so  many  different  kinds  of  conditions  that  may  take 
part  in  the  control  of  plant  processes,  and  each  of  these  condi- 
tions may  be  effective  with  so  many  different  intensities.  The 
complexity  and  newness  of  these  dynamic  problems  explain  the 
fact  that  the  very  methods  needed  for  the  sort  of  study  here 
suggested  are,  for  the  most  part,  still  to  be  devised.  It  is  ob- 
vious that  dynamic  physiological  investigations  must  rest  upon 
comparative  measurements  of  the  intensities  of  effective  condi- 
tions and  of  the  concomitant  or  resulting  rates  of  the  processes 
that  are  to  be  investigated,  so  that  studies  of  the  possible  ways 
by  which  such  measurements  and  comparisons  may  be  made 
must  constitute  the  beginnings  in  this  field.  All  of  our  work 
has  aimed  at  this  causal  sort  of  explanation  of  process  rates, 


345]  B.  E.  Livingston  147 

but  much  of  it,  as  so  far  carried  out,  has  resulted  in  little 
more  than  giving  us  certain  methods  of  study  and  certain 
incomplete  results.  The  problems  are  so  complex  that  broad 
generalizations  cannot  be  looked  for  for  a  long  time. 

It  has  so  happened  that  two  phases  of  dynamic  physiology 
have  thus  far  occupied  much  of  our  attention,  as  far  as 
research  is  concerned.  At  the  same  time,  these  two  phases  are 
among  the  most  fundamental  of  all,  as  regards  plant  growth 
in  general,  and  the  agricultural  and  forestal  production  of 
plant  material  in  particular,  and  they  also  appear  to  repre- 
sent the  very  simplest  problems  in  plant  control.  The  first 
of  these  phases,  or  groups  of  dynamic  problems,  deals  with 
the  water  relations  of  plants;  the  second  deals  with  their 
inorganic-salt  relations.  The  connotation  of  these  two  groups 
of  problems  may  be  roughly  suggested  to  the  reader  by  the 
statement  that  the  agricultural  operations  of  drainage  and 
irrigation  are  related  to  plant  water  relations,  while  fertilizer 
practice  is  related  to  inorganic-salt  relations.  A  large  number 
of  the  contributions  from  this  laboratory  have  dealt  with  one 
or  the  other  of  these  general  phases.  The  measurement  and 
experimental  control  of  the  environmental  conditions  of  mois- 
ture and  of  inorganic  salts,  and  the  relation  of  these  condi- 
tions to  plant  growth,  have  thus  received  a  large  portion  of 
our  attention. 

Along  with  the  study  of  external  conditions,  the  internal 
conditions  of  our  experimental  plants  must,  of  course,  receive 
consideration.  While  these  conditions  are  generally  much  more 
difficult  of  adequate  measurement  than  are  those  of  the  en- 
vironment, some  progress  has  nevertheless  been  made  in  this 
direction.  For  example,  the  work  of  this  laboratory  has 
aided  the  advance  of  our  knowledge  of  the  manner  in  which 
internal  conditions  control  the  rate  of  water-loss  from  plant 
leaves,  a  very  important  subject,  both  to  the  science  of  plant 
physiology  and  to  the  arts  of  agriculture  and  forestry. 

The  relations  of  temperature  and  of  oxygen  supply  have 
recently  begun  to  receive  attention  here,  as  well  as  the  light 


148  The  Department  of  Plant  Physiology  [346 

relation  (besides  its  consideration  as  a  term  in  the  water- 
relation).  The  complex  relation  holding  between  plant 
growth  and  what  is  generally  understood  by  the  vague  word 
climate,  also  enters  into  some  of  our  more  recent  undertakings. 

This  is  not  the  place  to  attempt  a  presentation  of  the  de- 
tailed results  so  far  obtained  in  the  research  work  of  the  Lab- 
oratory of  Plant  Physiology,  although  it  may  be  remarked  that 
some  apparently  valuable  results  have  already  rewarded  our 
efforts.  What  most  requires  emphasis  here  is,  however,  that  a 
large  amount  of  necessary  preparation  has  been  accomplished, 
getting  ready  for  rational  experimentation  in  the  future. 
Many  new  methods  of  operation  and  of  interpretation  have 
oeen  evolved,  and  it  appears  as  though  the  time  may  not  be 
remote  when  some  of  the  broader  aspects  of  the  conditional 
control  of  plant  activities  may  be  undertaken  with  some  prom- 
ise of  a  satisfactory  outcome.  Such  broader  problems  will 
probably  have  to  be  left  to  other,  institutions,  with  more  facili- 
ties and  larger  appropriations  than  are  now  generally  avail- 
able for  university  laboratories. 

To  summarize  the  last  few  paragraphs,  our  operations  have 
been  and  are  directed  toward  a  dynamic  analysis  of  plant 
activity.  The  point  of  view  here  employed  may  perhaps  be 
envisaged  if  the  reader  will  regard  the  living  plant  in  some- 
what the  same  general  way  as  he  might  any  complex  machine, 
such  as  a  gasoline  motor,  for  example.  To  understand  its 
working  one  must  understand  how  and  how  much  various  con- 
ditions may  affect  such  a  machine;  in  short,  he  must  become 
an  engineer  with  respect  to  that  particular  mechanism.  Dyna- 
mic plant  physiology  may  be  said,  then,  to  be  engineering  sci- 
ence as  applied  to  the  operations  of  the  living  plant.  It  can 
progress  only  through  quantitative  studies, — through  experi- 
mental tests  under  controlled  or  measured  conditions,  through 
the  comparison  of  efficiency  graphs  and  curve-tracings  made 
by  recording  instruments,  through  the  mathematical  interpre- 
tation of  relations  between  conditions  and  process  rates, 
etc., — and  it  is  with  just  this  sort  of  studies  that  our  inves- 
tigations have  to  do. 


347] 


B.  E.  Livingston 


149 


150          The  Department  of  Plant  Physiology  [348 

The  following  paragraphs  present  the  main  contributions 
thus  far  made  by  this  laboratory. 

The  water  relation  of  plants. — This  relation  involves  the 
plant  responses  that  result  from  alterations  in  the  supply  and 
in  the  consumption  or  loss  of  water.  For  temperate  regions  it 
is  the  main  conditional  relation  for  plant  growth  in  the  open, 
whether  the  plants  be  wild  or  cultivated.  Most  of  the  water 
necessary  for  plant  growth  is  given  off  into  the  air,  by  evap- 
oration from  the  plant  surfaces,  almost  as  soon  as  the  water  is 
taken  up  from  the  soil ;  the  amount  of  this  liquid  actually  con- 
sumed in  forming  the  plant  body  is  very  small.  Active  plants 
must  be  continuously  impregnated  with  water,  and  the  loss  by 
evaporation  may  be  likened  to  a  very  considerable  but  unavoid- 
able leak  in  a  steam  engine.  The  rate  of  water  supply  to  the 
plant  must  be  great  enough  to  counterbalance  this  loss  by 
evaporation,  or  the  growth  process  will  be  retarded.  To 
understand  the  plant  as  a  machine  it  is  thus  primarily  neces- 
sary to  study  the  conditions  that  control  the  rates  of  water- 
loss  and  of  water-intake. 

One  of  the  principal  conditions  that  affect  the  rate  of 
water-loss  by  evaporation  from  plants  is  the  evaporating 
power  of  the  air,  and  this  condition  needs  to  be  studied  quan- 
titatively.  To  accomplish  this  the  porous-cup  atmometer  has 
been  devised  and  perfected  during  the  last  decade,  most  of  the 
work  having  been  done  in  connection  with  this  laboratory. 
The  instrument,  in  various  forms,  is  now  widely  employed  by 
students  of  plant  growth.  The  readings  obtained  by  its 
means  may  be  regarded  as  measures  of  the  evaporating  power 
of  the  air  and  they  may  be  obtained  for  any  desirable  time 
intervals. 

Another  condition  that  takes  part  in  the  control  of  the  rate 
of  water  loss  from  plants  is  the  intensity  of  absorbed  radiant 
energy,  received  directly  or  indirectly  from  the  sun.  It  is 
therefore  requisite  to  measure  and  integrate  this  intensity  as 
it  affects  the  evaporation  of  water  from  moist  surfaces  such  as 
plant  leaves.  This  is  now  possible  by  the  use  of  the  radio- 


349]  B.  E.  Livingston  151 

atmometer,  which  has  also  been  devised  and  perfected  here, 
and  this  apparatus  is  likewise  coming  into  general  use. 

The  two  conditions  just  mentioned  are  both  effective  from 
without  the  plant;  they  are  external  conditions.  There  is  also 
an  internal  condition  (effective  from  within  the  plant)  that 
exerts  great  influence  upon  the  rate  of  evaporational  water- 
loss  from  plant  surfaces.,  and  this  has  been  called,  in  our  dis- 
cussions, the  transpiring  power  of  the  plant.  Studies  largely 
carried  out  in  this  laboratory  have  resulted  in  the  perfection 
of  methods  by  which  the  intensity  of  this  internal  condition 
may  be  evaluated,  and  integrated  over  convenient  time  periods. 
Reference  is  here  made  to  the  method  of  relative  transpiration 
and  to  that  of  cobalt-chloride  paper.  Both  are  now  frequently 
employed  in  studies  of  plant  growth. 

As  has  been  mentioned,,  the  rate  of  water-supply  to  the 
plant  also  requires  attention  in  studies  of  the  water  relations. 
This  is  primarily  the  water-supplying  power  of  the  soil, 
another  external  condition.  The  need  for  quantitative  study 
of  this  has  led  to  investigations  in  the  realm  of  soil  physics, 
and  our  efforts  have  already  resulted  in  some  useful  methods 
of  approach,  but  more  work  will  be  necessary  before  we  can 
deal  with  this  subterranean  condition  as  satisfactorily  as  is 
now  possible  with  the  conditions  that  are  effective  above  the 
soil.  Out  of  our  work  has  come  the  auto-irrigator,  an  instru- 
ment  which  maintains  the  moisture  conditions  of  the  soil 
nearly  constant  throughout  long  periods  of  time.  Its  readings 
indicate  the  rates  at  which  an  experimental  plant  removes 
water  from  a  soil  mass  thus  automatically  supplied  with 
water.  The  auto-irrigator  is  now  employed  by  many  experi- 
menters, in  cases  where  it  is  desired  to  maintain  a  constant 
soil-moisture  content.  Soil  osmometers  have  also  been  em- 
ployed in  the  study  of  the  water-supplying  power  of  the  soil  as 
related  to  absorption  by  plant  roots. 

By  the  employment  of  these  various  methods,  all  perfected 
here  within  the  last  few  years,  we  have  been  able  to  begin  to 
understand  some  of  the  more  fundamental  features  of  the 


152          The  Department  of  Plant  Physiology  [350 

plant  water  relation,   and  the  near  future  promises  much 
greater  advances. 

The  inorganic  salt  relation  of  plants. — This  relation  involves 
the  plant  responses  that  result  from  alterations  in  the  supply 
and  in  the  consumption  or  loss  of  inorganic  salts.  So  far  as 
studies  of  this  relation  have  progressed,  these  have  dealt 
mainly  with  the  power  of  the  surroundings  to  deliver  inor- 
ganic salts  (or  the  ions  into  which  they  dissociate)  to  plant 
roots,  as  this  power  is  related  to  growth.  This  aspect  of  this 
relation  has  formed  the  subject  of  very  many  experimental 
investigations  during  the  past  century,  but  the  work  of  this 
laboratory  has  approached  the  problem  from  a  somewhat  new 
point  of  view. 

The  soil  presents  such  a  very  complicated  physical  and 
chemical  system  that  it  is  quite  hopeless,  for  the  present,  to 
attempt  to  understand  the  behavior  of  soil  salts  in  any  way 
adequate  to  the  needs  of  plant  physiology,  and  our  attention 
has  been  turned  exclusively  to  the  study  of  plant  growth  in 
nutrient  solutions  and  in  sand  cultures.  For  the  growth  of 
ordinary  plants  it  requires  only  seven  ions  of  inorganic  salts 
to  produce  satisfactory  growth,  these  being:  potassium  (K), 
calcium  (Ca),  magnesium  (Mg),  iron  (Fe),  nitrate  (No3), 
sulphate  (S04),  and  phosphate  (P04).  Iron  is  needed  in 
relatively  but  very  small  "amount,  it  being  only  necessary  that 
the  solution  bathing  the  plant  roots  shall  contain  a  trace  of 
this  ion.  Variations  in  the  partial  concentrations,  or  in  the 
supply,  of  the  other  six  ions  may  produce  marked  alterations 
in  growth,  however,  and  it  is  with  reference  to  these  that  our 
work  was  begun.  By  means  of  elaborate  series  of  different 
culture  solutions  the  effects  upon  the  plant,  of  altering  the  salt 
proportions  in  the  nutrient  medium,  have  been  experimentally 
studied.  It  has  been  possible  to  devise  a  3-salt  nutrient  solu- 
tion for  use  as  a  standard,  in  which  the  three  salts  (CaN03; 
MgS04  and  KH2P04)  are  present  in  proper  proportions  to 
produce  a  physiologically  balanced  solution,  producing  excel- 
lent growth.  The  proper  salt  proportions  for  any  plant  form, 


351]  B.  E.  Livingston  153 

and  for  any  given  complex  of  external  conditions  may  readily 
be  determined.  All  the  various  standard  nutrient  solutions 
heretofore  employed  have  contained  at  least  four  salts  (besides 
the  trace  of  iron),  and  have  been  correspondingly  more  com- 
plex and  difficult  to  handle  and  interpret.  This  work  applies 
to  many  phases  of  the  art  of  fertilizer  practice,  as  employed  in 
agriculture,  and  it  furnishes  a  method  by  which  we  may  now 
begin  to  study  the  salt  relation  as  influenced  by  the  condi- 
tions of  the  water  relation,  the  temperature  relation,  etc. 

The  effects  of  some  other  inorganic  ions  upon  plants  have 
begun  to  receive  attention  here,  also  the  effects  of  variations 
in  the  oxygen  content  of  the  soil. 

The  relation  of  plants  to  climatic  conditions. — The  main 
climatic  conditions  that  affect  plants  are  air  temperature, 
atmospheric  evaporating  power,  and  the  effective  intensity  If 
solar  radiation.  Other  climatic  -conditions  generally  affect 
plants  only  indirectly;  for  example,  rainfall  influences  the 
water-supplying  power  of  the  soil. 

The  studies  thus  far  undertaken  in  this  laboratory  have 
dealt  with  an  attempt  to  find  out  in  what  manner  and  to  what 
degree  the  annual  march  of  the  complex  of  climatic  condi- 
tions may  be  related  to  the  corresponding  annual  or  seasonal 
march  of  plant  growth-rates.  From  these  studies  has  been 
developed  -a  method  by  which  it  appears  possible  to  compare 
climates  (of  different  places  at  the  same  time  or  of  the  same 
place  at  different  times)  in  terms  of  the  growth-rates  of  a 
standard  plant.  The  plant  is  thus  employed  as  an  auto- 
matically weighting  and  integrating  instrument. 

This  general  relation  is  of  great  importance  to  agriculture 
and  forestry  and  the  point  of  view  here  taken  (that  of  the 
conditional  control  of  plant  processes)  is  attracting  the  atten- 
tion of  investigators  in  these  subjects.  The  problems  are 
exceedingly  complex,  but  progress  is  being  slowly  made. 

The  reader  will  be  able  to  form  a  somewhat  more  concrete 
conception  of  what  has  thus  far  been  accomplished,  by  refer- 
ence to  the  list  of  publications  from  this  department,  which 
follows  the  present  paper. 


154  Publications  from  the  Laboratory  [352 


LIST   OF   PUBLICATIONS   FROM   THE   LABORATORY   OF 
PLANT  PHYSIOLOGY 


October,  1909, to  February,  1917. 

(Arranged  by  years,  the  year  beginning  October  1.) 


1909-1910 

BROWN,  W.  H.,  and  L.  W.  SHARP,    The  closing  response  in  Dionaea. 
Bot.  Gaz.  49:  290-302.     1910. 

HAWKINS,  LON  A.,     The  porous  clay  cup  for  the  automatic  watering 
of  plants.     Plant  World  13:  220-227.     1910. 

LIVINGSTON,  B.  E.,  The  heath  of  Ltineburg.     Plant  World  12:  231- 
237.     1909. 

A    rain-correcting    atmometer    for    ecological    instrumentation. 

Plant  World  13:  79-82.     1910. 

—  Operation  of  the  porous  cup  atmometer.     Plant  World  13:  111- 
118.     1910. 

Evaporation  and  other  climatic  factors  in  relation  to  the  distri- 
bution of  plants.    Carnegie  Inst.  Wash.  Year  Book  8:  62.  1910. 
Atmometry  and  the  relation  of  evaporation  to  other  factors.     Car- 
negie Inst.  Wash.  Year  Book  8:  62.     1910. 

The  physics  of  transpiration  in  plants.     Carnegie  Inst.  Wash . 

Year  Book  8:  62.     1910. 

Soil-moisture  in  relation  to  plant  growth.    Carnegie  Inst.  Wash. 

Year  Book  8:  63.     1910. 

1910-11 

BROWN,  W.  H.,  Evaporation  and  plant  habitats  in  Jamaica.     Plant 

World  13:  268-272.     1910. 
LIVINGSTON,  B.  E.,     Relation  of  soil  moisture  to  desert  vegetation. 

Bot.  Gaz.  50:  241-255.     1910. 
A  radio-atmometer  for  comparing  light  intensities.     Plant  World 

14:  96-99.     1911. 
The  relation  of  the  osmotic  pressure  of  the  cell  sap  in  plants  to 

arfd  habitats.     Plant  World  14:  153-164.     1911. 
—  Evaporation  and  soil  moisture.     Carnegie  Inst.  Wash.  Year  Book 

9:  58-59.     1911. 

1911-12 

BROWN,  W.  H.,     The  relation  between  soil  moisture  content  and  the 
conditions  of  the  aerial  environment  of  plants  at  the  time  of 


353]  of  Plant  Physiology  155 

wilting.      (Preliminary  abstract.)     Johns  Hopkins  Univ.  Circ. 
whole  number  242:  26-28.     1912. 

BROWN,  W.  H.,  The  relation  of  evaporation  to  the  water  content  of 
the  soil  at  the  time  of  wilting.  Plant  World  15:  121-134. 
1912. 

JONES,  W.  R.,     The  digestion  of  starch  in  germinating  peas.      (Pre- 
liminary abstract.)     Johns  Hopkins  Univ.  Circ.  whole  number 
242:  29-30.     1912. 
-Same  title.    Plant  World  15:  176-182.     1912. 

LIVINGSTON,  B.  E.,  The  new  laboratory  of  plant  physiology  at  Home- 
wood.  Johns  Hopkins  Univ.  Circ.  whole  number  242:  7-10. 
1912. 

—  The  resistance  offered  by  leaves  to  transpirational  water  loss. 

(Preliminary   abstract.)     Johns   Hopkins   Univ.    Circ.   whole 
number  242:  11-13.     1912. 

—  Present  problems  in  soil  physics  as  related  to  plant  activities. 

Amer.  Nat.  66:  294-301.     1912. 
The   choosing  of   a  problem   for  research   in  plant  physiology. 

Plant  World  15:  73-82.     1912. 
—  A  schematic  representation  of  the  water  relations  of  plants,  a 

pedagogical  suggestion.     Plant  World  15:  214-218.     1912. 
—  —  A    rotating    table    for    standardizing    porous    cup    atmometers. 

Plant  World  15:  157-162.     1912. 
-     —Incipient  drying  in  plants.      (Abstract.)      Science  n.  s.  35:  394- 

395.     1912. 

—  Evaporation  and  soil-moisture.    Carnegie  Inst.  Wash.  Year  Book 

10:  64-65.     1912. 

LIVINGSTON,  B.  E.,  and  A.  H.  ESTABEOOK.  Observations  on  the  degree 
of  stomatal  movement  in  certain  plants.  (Preliminary  ab- 
stract.) Johns  Hopkins  Univ.  Circ.  whole  number  242:  24-25. 
1912. 

—  Same  title.     Bull.  Torr.  Bot.  Club  39:  15-22.     1912. 
LIVINGSTON,  B.  E.,  and  F.  SHEEVE.    The  relation  between  climatic  con- 
ditions and  plant  distribution  in  the  United  States.     Johns 
Hopkins  Univ.  Circ.  whole  number  242:  19-20.     1912. 

SHEEVE,  EDITH  B.,  A  calorimetric  method  for  the  determination  of 
leaf  temperatures.  Johns  Hopkins  Univ.  Circ.  whole  number 
242:  36-38.  1912. 

LIVINGSTON,  B.  E.,  and  W.  H.  BEOWN.  Relation  of  the  daily  march  of 
transpiration  to  variations  in  the  water  content  of  foliage 
leaves.  (Preliminary  abstract.)  Johns  Hopkins  Univ.  Circ. 
whole  number  242:  21-23.  1912. 

—  Same  title.     Bot.  Gaz.  53:  309-330.     1912. 

HAWKINS,  LON  A.  The  effect  of  certain  chlorides,  singly  and  combined 
in  pairs,  on  the  activity  of  malt  diastase.  (Preliminary  ab- 


156  Publications  from  the  Laboratory  [354 

stract.)     Johns  Hopkins  Univ.  Circ.  whole  number  242:  34-35. 
1912 

1912-13 

BROWN,  W.  H.,     The  relation  of  the  substratum  to  the  growth  of 

Elodea.     Philippine  Jour.  Sci.  8:  1-20.     1913. 
CALDWELL,  J.   S.,  The  relation  of  environmental  conditions  to  the 

phenomenon  of  permanent  wilting  in  plants.     Physiol.  Res.  I : 

1-56.     1913.     (Work  done  at  Desert  Laboratory,  directed  by 

B.  E.  Livingston.) 
HARVEY,  E.  M.,    The  action  of  the  rain-correcting  atmometer.    Plant 

World  16:  89-93.     1913.     (Work  done  at  Desert  Laboratory, 

directed  by  B.  E.  Livingston.) 

HAWKINS,  LON  A.,  The  effect  of  certain  chlorides,  singly  and  com- 
bined in  pairs,  on  the  activity  of  malt  diastase.  Bot.  Gaz. 

55:  265-285.     1913. 
The  influence  of  calcium  magnesium  and  potassium  nitrates  upon 

the  toxicity  of  certain  heavy  metals  toward  fungus   spores. 

Physiol.  Res.  1 :  57-91.     1913. 
HOYT,  W.  D.,     Some  toxic  and  antitoxic  effects  in  cultures  of  Spiro- 

gyra.     Bull.  Torr.  Bot.  Club  40:  333-360.     1913.     (Edited  by 

B.  E.  Livingston.) 
LIVINGSTON,  B.  E.,     The  resistance  offered  by  leaves  to  transpiration- 

al  water  loss.    Plant  World  16:  1-35.     1913. 
Adaptation  in  the  livir^  and  non-living.     Amer.  Nat.  47:  72-82. 

1913. 
Osmotic  pressure  and  related  forces  as  environmental  factors. 

Plant  World  16:  165-176.     1913. 
Climatic  areas  of  the  United  States  as  related  to  plant  growth. 

Proc.  Amer.  Phil.  Soc.  52:  257-275.     1913. 
The  water  relations  of  plants.     Carnegie  Inst.  Wash.  Year  Book 

II:  60-61.     1913. 

1913-14 

HOYT,  W.  D.,  Some  effects  of  colloidal  metals  on  Spirogyra.  Bot. 
Gaz.  57:  193-212.  1914.  (Edited  by  B.  E.  Livingston.) 

LIVINGSTON,  B.  E.,  The  water  relations  of  plants.  Carnegie  Inst. 
Wash.  Year  Book  12:  77-79,  1914. 

LIVINGSTON,  B.  E.,  and  GRACE  J.  LIVINGSTON.  Temperature  coeffi- 
cients in  plant  geography  and  climatology.  Bot.  Gaz.  56:  349- 
375.  1913. 

SHIVE,  J.  W.,  and  B.  E.  LIVINGSTON.  The  relation  of  atmospheric 
evaporating  power  to  soil  moisture  content  at  permanent 
wilting  in  plants.  Plant  World  17:  81-121.  1914. 

TOTTINGHAM,  W.  E.,  A  quantitative  chemical  and  physiological  study 
of  nutrient  solutions  for  plant  cultures.  Physiol.  Res.  I : 
133-245.  1914. 


355]  of  Plant  Physiology  157 

1914-15 

FBEE,  E.  E.,  A  relative  score  method  of  recording  comparisons  of 
plant  conditions  and  other  unmeasured  characters.  Plant 
World,  18:  249-256.  1915. 

^LIVINGSTON,  B.  E.,  Atmometry  and  the  porous  cup  atmometer.  Plant 
World  18:  21-30,  51-74,  95-111,  143-149.  1915. 

A  modification  of  the  Bellani  porous  plate  atmometer.     Science 

n.  s.  41:  872-874.     1915. 

^  Atmospheric  influence  on  evaporation  and  its  direct  measure- 
ment. Monthly  Weather  Rev.  3:  126-131.  1915. 

Spherical   porous   cups   for   atmometry.     Carnegie   Inst.    Wash. 

Year  Book  13:  84-85.     1915. 

LIVINGSTON,  B.  E.,  and  LON  A.  HAWKINS.  The  water-relation  be- 
tween plant  and  soil.  Carnegie  Inst.  Wash.  Pub.  204:  1-48. 
1915. 

„  LIVINGSTON,  B.  E.,  and  ALEITA  HOPPING.  Permanent  standardiza- 
tion of  cobalt-chloride  paper  for  use  in  measuring  the  tran- 
spiring power  of  plant  surfaces.  Carnegie  Inst.  Wash.  Year 
Book  13:  87.  1915. 

x- LIVINGSTON,  B.  E.,  and  A.  L.  BAKKE.  The  transpiring  power  of  plant 
foliage,  as  measured  by  the  method  of  standardized  hygromet- 
ric  paper.  Carnegie  Inst.  Wash.  Year  Book  13:  86-87.  1915. 

LIVINGSTON,  B.  E.,  and  J.  W.  SHIVE.  The  non-absorbing  atmometer. 
Carnegie  Inst.  Wash.  Year  Book  13:  83-84.  1915. 

Relation  between  atmospheric  conditions  and  soil  moisture  con- 
tent at  permanent  wilting  of  plants.  Carnegie  Inst.  Wash. 
Year  Book  13:  86.  1915. 

LIVINGSTON,  B.  E.,  and  H.  C.  SAMPSON.     Atmometric  units.     Carnegie 

Inst.  Wash.  Year  Book  13:  85.     1915. 

^LIVINGSTON,  B.  E.,  and  LON  A.  HAWKINS.  The  water-attracting  pow- 
er of  soil,  as  measured  by  the  rate  of  loss  for  the  auto-irri- 
gator.  Carnegie  Inst.  Wash.  Year  Book  13:  86.  1915. 

LIVINGSTON,  B.  E.,  and  H.  E.  PULLING.  The  water-supplying  power 
of  the  soil.  Carnegie.  Inst.  Wash.  Year  Book  13:  86-87.  1915. 

McLEAN,  F.  T.,  Relation  of  climate  to  plant  growth  in  Maryland. 
Monthly  Weather  Rev.  43:  65-72.  1915. 

PULLING,  H.  E.  and  B.  E.  LIVINGSTON.  The  water-supplying  power 
of  the  soil  as  indicated  by  osmometers.  Carnegie  Inst.  Wash. 
Pub.  204:  51-84.  1915. 

SHIVE,  J.  W.,  The  freezing  points  of  Tottingham's  nutrient  solutions. 
Plant  World  17:  345-353.  1915. 

An  improved  non-absorbing  porous  cup  atmometer.     Plant  World 

18:  7-10.     1915. 


158  Publications  from  the  Laboratory  [356 

SHIVE,  J.  W.,  A  three-salt  nutrient  solution  for  plants.  Amer.  Jour. 
2:  157-160.  1915. 

1915-16 

BAKKE,  A.  L.,  and  B.  E.  LIVINGSTON.  Further  studies  on  foliar  tran- 
spiring power  in  plants.  Physiol.  Res.  2:  51-71.  1916. 

FREE,  E.  E.,  An  ancient  bajada  of  the  Great  Basin  region.  Carnegie 
Inst.  Wash.  Year  Book  14:  95.  1916. 

FREE,  E.  E.,  and  B.  E.  LIVINGSTON.  The  relation  of  soil  aeration  to 
plant  growth.  Carnegie  Inst.  Wash.  Year  Book  14:  60-61. 
1916. 

JOHNSTON,  E.  S.,  and  B.  E.  LIVINGSTON.  Measurement  of  evapora- 
tion for  short  time  intervals.  Plant  World  19:  119-150. 
1916. 

LIVINGSTON,  B.  E.,  Physiological  indices  of  temperature  efficiency 
for  plant  growth.  Carnegie  Inst.  Wash.  Year  Book  14:  61-62. 
1916. 

—  A  simple  climatic  index.     Carnegie  Inst.  Wash.  Year  Book  14: 

62.     1916. 

—  Plane  porous   clay   surfaces   for   use  in   atmometry.     Carnegie 

Inst.  Wash.  Year  Book  14:  76.     1916. 

Auto-irrigation  of  pots  of  soil  for  experimental  cultures.  Car- 
negie Inst.  Wash.  Year  Book  14:  76.  1916. 

—  Physiological  temperature  indices  for  the  study  of  plant  growth 

in  relation  to  climatic  conditions.  Physiol.  Res.  1 :  399-420. 
1916. 

* A  single  index  to  represent  both  moisture  and  temperature  con- 
ditions as  related  to  plant  growth.  Physiol.  Res.  1 :  421-440. 
1916. 

—  A  record  of  the  doctors  in  botany  of  the  University  of  Chicago, 

1897-1916.  Presented  to  John  Merle  Coulter,  Professor  and 
head  of  the  Department  of  Botany,  by  the  Doctors  in  Botany, 
at  the  Quarter-Centennial  of  the  University,  June,  1916.  vii 
+  87  p.  Chicago,  1916.  (Edited  by  B.  E.  Livingston.) 

LIVINGSTON,  B.  E.,  and  E.  S.  JOHNSTON.  Influence  of  solar  radia- 
tion as  a  drying  agent.  Carnegie  Inst.  Wash.  Year  Book  14: 
75.  1916. 

McCATj,,  A.  G.,  A  new  method  for  the  study  of  plant  nutrients  in 
sand  cultures.  Jour.  Amer.  Soc.  Agron.  7:  249-252.  1915. 

The  absorption  by  soils  of  potassium  from  aqueous  solution  of 

potassium  chloride.  Carnegie  Inst.  Wash.  Pub.  230:  167-175. 
1915. 

—  A  method  for  the  renewal  of  plant  nutrients  in  sand  cultures. 

Ohio  Jour.  Sci.  16:  101-103.     1916. 


357]  of  Plant  Physiology  159 

McCALL,  A.  G.,  The  availability  of  nutrient  salts.  Jour.  Amer.  Soc. 
Agron.  8:  47-50.  1916. 

Field  and   laboratory  studies   of   soils,     viii  +  133   p.,  54   figs. 

New  York,  1916. 

McCALL,  A.  G.,  F.  M.  HILDEBEANDT  and  E.  S.  JOHNSTON.  The  ab- 
sorption of  potassium  by  the  soil.  Jour.  Phys.  Chem.  20: 
51-63.  1916. 

SHAW,  C.  F.,  and  E.  E.  FEEE.  Agronomic  and  soil  conditions  in  the 
Selby  Smoke  Zone.  U.  S.  Bur.  Mines,  Bull.  98:  451-473. 
1915. 

SHIVE,  J.  W.,  A  study  of  physiological  balance  in  nutrient  media. 
Physiol.  Res.  I:  327-397.  1915. 

TEELEASE,  S.  F.,  and  B.  E.  LIVINGSTON,  Foliar  transpiring  power 
and  the  Darwin  and  Pertz  porometer.  Carnegie  Inst.  Wash. 
Year  Book  14:  76-77.  1916. 

• The  daily  march  of  transpiring  power  as  indicated  by  the  por- 
ometer and  by  standardized  hygrometric  paper.  Jour.  Ecol. 
4:  1-14.  1916. 

1916-17 

CANNON,  W.  A.  and  E.  E.  FEEE.  The  ecological  significance  of  soil 
aeration.  Science  n.  s.  45:  178-180.  1917. 

FEEE,  E.  E.,  An  ancient  lake  basin  on  the  Mohave  river.  Carnegie 
Inst.  Wash.  Year  Book  15:  90-91.  1917. 

Underground  structure  and  artesian  water  in  desert  valleys  of 

the  Great  Basin.  'Carnegie  Inst.  Year  Book  15:  91-94.  1917. 

LIVINGSTON,  B.  E.,  A  quarter-century  of  growth  in  plant  physiology. 
Plant  World  20:  1-15.  1917. 

The  laboratory  of  plant  physiology.  Johns  Hopkins  Univ.  Circ., 

whole  number  290:  40-45.  1916. 

LIVINGSTON,  B.  E.,  and  E.  E.  FEEE,  Relation  of  soil  aeration  to  plant 
growth.  Carnegie  Inst.  Wash.  Year  Book  15:  78.  1917. 

LIVINGSTON,  B.  E.,  and  EDITH  B.  SHEEVE,  Improvements  in  the  meth- 
od for  determining  the  transpiring  power  of  plant  surfaces 
by  hygrometric  paper.  Plant  World  19:  287-309.  1916- 

LIVINGSTON,  B.  E.,  and  F.  SHEEVE,  The  role  of  climatic  factors  in 
determining  the  distribution  of  vegetation  in  the  United 
States.  Carnegie  Inst.  Wash.  Year  Book  15:  69-72.  1917. 

PULLING,  H.  E.,  The  angular  micrometer  and  its  use  in  delicate  and 
accurate  microscopic  measurements.  Amer.  Jour.  Bot.  8: 
393-406.  1916. 


160  Atmometric  Units  [358 

ATMOMETRIC  UNITS 

BY  BURTON"  E.  LIVINGSTON 

The  increasing  interest  in  atmometry  1  and  the  fact  that 
this  subject  is  becoming  recognized  as  of  general  and  funda- 
mental importance  in  many  branches  of  scientific  and  practical 
endeavor,  make  it  desirable  that  there  be  some  uniformity  in 
our  conceptions  as  to  the  units  employed  in  atmometric  meas- 
urements. To  approach  the  subject  it  is  first  necessary  that 
the  purpose  of  atmometric  observations  be  clearly  in  mind; 
much  vagueness  still  prevails  in  this  connection.  The  rate 
of  evaporation  of  water  from  any  surface  is  dependent  on 
two  sets  of  conditions.  One  set  (internal  ones)  are  effective 
in  or  behind  the  surface  and  the  other  (external  ones)  are 
effective  in  front  of  the  surface,  that  is,  in  the  gas  phase  of 
the  system.  The  internal  conditions  are  the  characteristics 
of  the  evaporating  surface  and  include  such  features  as  the 
concentration  of  solutes  in  the  liquid  water,  the  influence  ex- 
erted by  the  presence  of  a  solid  in  which  the  water  is  imbibed, 
the  shape  and  extent  of  the  surface,  its  direction  of  exposure, 
its  ability  to  absorb  or  emit  radiant  energy,  the  heat-conduct- 
ing capacity  of  the  material  back  of  the  surface,  etc.  The 
external  conditions  include  primarily  four  characteristics  of 
the  space  in  front  of  the  evaporating  surface :  the  temperature 
of  the  gas  phase,  its  moisture  condition,  the  influence  of  move- 
ment or  circulation  of  the  gas  over  the  surface,  and  the  effec- 
tive intensity  of  impinging  radiation.  I  have  used  the  term 


1 1  employ  the  word  as  synonymous  with  and  shorter  than  atmid- 
ometry,  just  as  I  have  adopted  atmometer  in  place  of  its  rival,  atmid- 
ometer.  Both  are  etymologically  correct,  but  the  one  formed  from 
the  root  atmo,  besides  being  shorter,  has  received  the  sanction  of  an 
international  meteorological  congress.  Atmometer  seems  to  have 
been  coined  by  Sir  John  Leslie,  1813.  (See  Livingston,  B.  E., 
"  Atmometry  and  the  porous  cup  atmometer."  Plant  World  18:  21-30, 
51-74,  95-111,  143-149.  1915.  Other  papers  are  there  cited.) 


359]  B.  E.  Livingston  161 

evaporating  power  of  the  air  to  include  the  first  three  of  these, 
since  the  gas  phase  is  air  in  most  studies  and  since  these  three 
features  are  properties  of  this  gas.  The  fourth  feature  de- 
pends only  indirectly,  and  to  a  comparatively  slight  degree, 
upon  the  characteristics  of  the  gas  phase  next  to  the  evaporat- 
ing surface.  In  climatological  atmometry  this  is  the  effective 
intensity  of  solar  radiation,  direct  or  indirect,  which  depends 
upon  the  season,  the  time  of  day  and  the  state  of  the  sky,  as 
well  as  upon  the  nature  of  reflecting  surfaces  in  the  vicinity. 

Since  evaporation  is  a  process  and  not  a  state  of  matter,  its 
magnitude  has  to  be  expressed  in  terms  of  time  rates.  While 
temperature,  for  instance  (being  a  state  of  matter),  may  be 
expressed  in  degrees  on  a  thermometer  scale,  evaporation  in- 
tensities must  be  stated  as  the  amount  of  water  evaporated 
in  a  unit  of  time.  Atmospheric  evaporating  power  refers 
to  the  external  surroundings  of  the  evaporating  surface  (usu- 
ally to  the  air  space  above  it,  about  it,  etc.)  and  it  need  not 
specifically  refer  to  the  air  itself,  for  if  there  were  no  air 
present  this  space  would  still  possess  an  evaporating  power. 
The  evaporating  power  of  the  air  over  a  surface  is  considered 
as  proportional  to  the  reciprocal  of  the  tendency  of  all  the 
conditions  effective  in  the  space  over  that  surface  to  resist  the 
vaporization  of  water  therefrom. 

There  have  been  some  who  have  objected  to  this  expres- 
sion, but  they  have  not  put  forward  another  term.  From  a 
long-continued  attempt  to  acquire  modes  of  expression  by 
which  we  may  hope  to  deal  with  the  dynamic  aspect  of  plant 
and  animal  environments  an  alternative  expression  has  devel- 
oped, which  may  be  brought  forward  here. 

In  all  considerations  of  the  dynamic  relations  between  or- 
ganisms and  their  surroundings  we  find  it  valuable  to  con- 
sider the  internal  and  the  external  complexes  of  influential 
conditions  separately,  and  each  group  of  conditions  may  be 
expressed,  for  any  process  we  may  have  to  deal  with,  as  a 
single  value  or  index.  We  may  thus  speak  of  the  index  of 
transpiring  power,  the  index  of  environmental  radiation,  and 
11 


162  Atmometric   Units  [360 

the  index  of  the  evaporating  power  of  the  air.  From  this  last 
expression  comes  the  new  term,  the  atmometric  index  of  the 
locality  and  time  period  considered. 

The  atmometric  index  is  the  relative  measure  of  the  evapo- 
rating power  of  the  air,  and  it  is  to  be  expressed  as  a  possible 
time  rate  of  doing  work ;  it  is  an  index  of  a  power.  The  unit 
of  measurement  must  therefore  be  a  unit  of  work,  but  it  may 
just  as  well  be  a  unit  of  process  rate,  if  the  same  process  be 
always  employed.  Thus  it  may  be  stated  as  the  amount  of 
water  evaporated  per  unit  of  time.  If  the  liquid  water  were 
always  at  the  same  temperature  this  would  actually  be  a 
measure  of  work.  That  the  water  of  evaporating  surfaces 
varies  in  temperature  has  been  thus  far  neglected  in  this 
whole  line  of  enquiry,  the  errors  thus  arising  being  relatively 
small  in  the  present  early  stages  of  our  studies. 

To  determine  the  numerical  value  of  the  atmometric  index, 
we  must  also  consider  a  factor  representing  some  standard  unit 
of  surface.  It  has  been  seen  above  that  the  power  of  any  sur- 
face to  give  off  water  vapor  is  determined  by  the  character- 
istics of  that  surface,  and  that  the  extent  of  the  surface  is  not 
by  any  means  the  only  characteristic  that  needs  to  be  con- 
sidered. The  shape  and  the  direction  of  exposure  of  the  sur- 
face must  be  taken  into  account,  and  also  the  influence  of  the 
non-aqueous  materials  that  are  in  or  behind  the  surface,  etc. 
It  is-  therefore  impossible  to  employ  a  surface  unit  defined  by 
area  alone.  As  soon  as  this  is  realized  all  attempts  to  ex- 
press the  atmometric  index  as  a  time  rate  of  evaporation  from 
a  square  centimeter  (etc.)  of  free  water  surf  ace  .are  seen  to  be 
quite  useless.  A  free  water  surface  is  more  or  less  nearly 
plane  and  more  or  less  nearly  horizontal  (depending  upon  the 
wind  velocity,  among  other  things),  but  it  may  be  of  any 
shape  or  size,  and  all  these  characteristics  are  important. 
With  a  given  set  of  aerial  conditions  two  different  atmometer 
pans,  for  instance,  can  give  off  the  same  amount  of  water  per 
hour,  per  square  centimeter  of  surface,  only  when  they  are  of 
the  same  size  and  shape.  Also,  the  depth  of  the  water  and 


361]  B.  E.  Livingston  163 

the  nature  of  the  pans  themselves  must  be  exactly  alike.  It 
is  thus  both  theoretically  and  practically  impossible  to  express 
the  surface  factor  in  the  atmometric  index  by  a  unit  that  rep- 
resents merely  extent  of  surface. 

Since  the  complex  of  internal  conditions  that  make  up  the 
capacity  of  any  surface  to  produce  evaporation  is  very  difficult 
of  analysis,  we  may  avoid  the  necessity  of  this  analysis  by 
simply  using  atmometer  surfaces  that  act  alike.  Then  the 
surface  factor  of  our  unit  of  measurement  becomes  the  surface 
of  our  instrument  (with  whatever  characteristics  it  may  have), 
and  we  do  not  need  to  enquire  what  may  be  its  area,  etc.  In  all 
the  studies  so  far  carried  out  with  porous  clay  and  paper  sur- 
faces for  measuring  the  evaporating  power  of  the  air,  I  have 
never  been  led  to  determine  the  area  of  the  surface  employed ; 
it  would  have  been  useless  to  do  so,  although  such  a  surface 
is  easily  measured.  We  are  thus  led  to  the  proposition  that 
the  atmometric  index  is  to  be  expressed  in  terms  of  (1)  a 
weight  unit  of  water,  (2)  a  time  unit,  and  (3)  a  given  stan- 
dard instrument.  All  these  desiderata  are  supplied  in  such 
a  statement  as  this :  that  the  evaporating  power  of  the  air  in 
a  given  locality  and  for  a  given  period  is  such  as  to  produce 
the  evaporation  of  so  and  so  many  grams  of  water  per  hour 
from  a  standard  spherical  porous-cup  atmometer.  .  No  unit  of 
area  is  considered,  although  all  the  internal  characteristics  of 
the  instrument  are  implied  by  its  name. 

It  is  clear  that  it  makes  no  difference  what  sort  of  surface 
we  may  use  as  standard,  but  we  must  use  the  same  standard 
throughout  any  series  of  comparative  measurements,  and  when 
several  instruments  are  needed  we  must  be  sure  that  their  in- 
ternal characteristics  are  as  nearly  alike  as  possible,  as  far  as 
these  characteristics  may  influence  the  rate  of  evaporation. 
The  only  feasible  way  to  compare  a  number  of  instruments 
in  this  last  regard  is  to  place  them  all  in  the  same  environ- 
ment (as  far  as  environmental  characteristics  may  influence 
the  rate  of  evaporation)  and  then  compare  their  evaporation 
rates.  If  these  rates  differ  this  must  be  because  of  internal 


164  Atmometric   Units  [362 

differences  in  the  instruments.  That  two  porous  cups  or 
pans  of  water  are  of  t'he  same  size,  shape,  color,  etc.,  does  not 
necessarily  indicate  that  they  may  be  expected  to  give  like 
readings  if  placed  in  the  same  environment,  for  other,  less 
easily  recognized  characteristics  of  the  instruments  may  not 
be  without  influence,  and  the  surfaces  may  differ  with  respect 
to  some  of  these.  This  consideration  leads  to  standardization 
and  the  use  of  a  rotating  table. 

By  this  procedure  an  index  is  obtained  that  represents  rela- 
tive capacity  of  each  of  the  instruments  tested,  to  give  off 
water  vapor,  and  the  index  of  each  one  is  expressed  as  a 
coefficient  of  correction,  a  number  by  which  the  readings  of 
that  instrument  are  to  be  multiplied  in  order  to  give  the  read- 
ing that  would  have  been  obtained  from  the  master  standard 
instrument  if  it  had  been  operated  for  the  same  time  and  at 
the  same  place.  If  an  instrument  is  effectively  just  like  the 
master  standard  its  coefficient  is  unity.  It  is  not  possible, 
however,  to  obtain  useful  coefficients  for  instruments  that 
differ  appreciably  from  the  standard  in  form,  size,  etc. 

Since  it  is  necessary  that  several  instruments  be  practically 
alike  if  their  readings  are  to  be  comparable,  it  is  highly  desir- 
able that  different  workers  use  as  few  different  forms  of  instru- 
ment as  possible.  For  studies  on  the  details  of  the  evaporation 
process  itself  various  kinds  of  surfaces  are  desirable,  but  for 
general  climatic  atmometry  the  number  of  kinds  should  be 
kept  as  small  as  may  be.  This  seems  to  be  not  at  all  well 
understood,  and  workers  who  have  not  taken  the  trouble  to 
appreciate  just  what  is  the  purpose  of  atmometric  measure- 
ments continue  to  construct  new  types  of  instruments  and  to 
employ  them.  For  example,  the  idea  is  abroad  that  if  the 
right  sort  of  instrument  might  be  devised  its  readings  would 
indicate  relative  rates  of  plant  transpiration.  Obviously  such 
an  instrument  would  have  to  alter  its  internal  conditions  from 
minute  to  minute,  just  as  would  occur  in  the  standard  plant 
individual,  and  all  other  plants  would  usually  differ  from  it. 
The  idea  is  bootless.  We  do  not  wish  to  measure  plant  tran- 


363]  B.  E.  Livingston  165 

spiration  but  to  measure  the  atmometric  index  of  the  air  in 
terms  of  its  effect  upon  a  standard  instrument  whose  internal 
conditions  do  not  change.  The  internal  conditions  of  each 
plant  or  group  of  plants  must  be  studied  in  relation  to  the  un- 
changing ones  of  the  instrument.  A  given  temperature  change 
does  not  affect  all  objects  or  processes  alike,  yet  we  do  not  con- 
struct a  new  thermometer  scale  for  each  object  or  process  with 
which  we  deal.  It  may  be  well  to  mention  in  this  connection 
that  atmometry  should  furnish  climatological  data  applicable 
to  many  fields  of  endeavor ;  the  animal  ecologist  requires  these 
data  as  much  as  does  the  plant  ecologist,  and  irrigation  en- 
gineers and  students  of  atmospheric  hygiene  and  ventilation 
all  have  use  for  atmometric  measurements. 

In  choosing  the  instrument  to  be  used  the  first  condition 
to  be  met  is  that  its  internal  conditions  or  characteristics 
should  not  alter;  they  should  be  uninfluenced  by  changes 
in  the  surroundings,  for  it  is  changes  in  the  latter  that  we  wish 
to  measure.  This  requirement  immediately  excludes  all  forms 
of  free  water  surfaces,  since  they  alter  with  wind,  etc.  Never- 
theless, since  an  open  pan  of  water  is  the  from  of  atmometer 
employed  by  the  U.  S.  Weather  Bureau,  since  this  is  the  sim- 
plest form  of  instrument  that  is  useful  in  any  way,  and  since 
data  obtained  with  this  pan  will  surely  prove  of  much  greater 
value  than  no  atmometric  data  at  all,  the  pan  of  water  must  be 
accepted  as  the  crudest  and  most  imperfect  form  of  atmome- 
ter. It  should  be  added  that  if  pans  of  water  are  used  they 
should  generally  be  of  the  same  form,  size,  etc.,  as  the  stand- 
ard recently  adopted  by  the  U.  S.  Weather  Bureau.  If  this  be 
adhered  to,  all  pan  measurements  will  be  comparable  among 
themselves  and  with  the  Weather  Bureau  data,  as  far  as  this  is 
possible  with  that  general  class  of  instruments. 

The  second  requirement  for  an  evaporating  surface  is  that 
it  should  be  as  sensitive  to  all  the  effective  conditions  of  the 
surroundings  as  is  possible,  without  any  alteration  in  its  in- 
ternal characteristics.  It  should  therefore  be  a  surface  that 
is  freely  exposed  to  wind  action.  A  nearly  ideal  surface  would 


166  Atmometric   Units  [364 

be  that  of  a  small,  spherical  droplet  of  water  suspended  freely 
in  the  air.  This  is  not  practicable,  but  the  Livingston  stan- 
dard spherical  porous  cup  seems  to  approach  this  desideratum 
as  nearly  as  is  possible  when  general  ease  of  manipulation  is 
considered.  Since  we  have  been  able  to  obtain  these  porcelain 
spheres  I  have  regarded  the  quest  for  a  practically  perfect 
surface  as  at  an  end.  Some  form  of  imbibed  porous  surface 
is  undoubtedly  best  for  general  purposes,  and  students  of 
ecology,  ventilation  engineers,  agriculturists,  etc.,  should 
avoid  the  free  water  surface  if  possible,  unless  it  is  desired  that 
the  results  obtained  be  roughly  comparable  with  those  obtained 
by  the  Weather  Bureau. 

A  third  requirement  is  not  as  important  now  as  it  will  be 
later,  after  more  atmometric  data  have  been  collected.  This 
is,  that  the  instrument  should  be  like  some  form  previously 
used,  so  as  to  give  data  that  may  be  comparable  with  at  least 
some  of  those  already  on  record. 

Of  the  different  forms  of  imbibed  porous  surface  there  are 
four  that  should  be  more  or  less  generally  useful :  the  Piche 
paper  disk,  the  Bellani  porous  clay  disk,  the  Babinet  cylinder 
and  the  Leslie  sphere,  the  last  three  having  been  recently  im- 
proved in  our  own  work.  Probably  more  measurements  have 
been  made  with  the  Piche  paper  disk  and  with  the  Livingston 
standard  cylinder  than  with  any  other  types  of  instrument, 
but  the  Piche  instrument  has  serious  practical  shortcomings 
and  the  sphere  is  more  nearly  perfect  than  the  cylinder.  The 
cylinder  will  remain  an  important  instrument  for  a  long  time 
but  the  sphere  will  almost  surely  .replace  it  eventually.  A 
fourth  feature  of  the  porous  sphere  may  be  emphasized  as 
desirable,  namely,  the  ready  applicability  of  this  type  of  in- 
strument to  the  measurement  of  effective  radiation  intensity, 
which  is  the  other  aerial  condition  of  evaporation  besides  the 
evaporating  power  of  the  air.  Since  we  have  been  able  to 
obtain  black  porous  spheres  of  the  same  size  as  the  white  ones, 
the  spherical  form  has  become  almost  essential  in  all  work  in 
atmometry  involving  radiation.  The  two  spheres,  one  white 


365]  B.  E.  Livingston  16'7 

and  one  black,  when  operated  together,  make  up  the  radio- 
atmometer,  for  use  in  studies  of  radiation  as  an  atmometric 
condition. 

Whatever  type  of  evaporating  surface  is  employed,  this  sur- 
face must  be  clearly  defined,  so  that  the  data  obtained  will  not, 
by  any  chance,  be  regarded  as  comparable  with  other  data 
derived  from  another  type  of  surface.  This  means  that  the 
essentials  of  the  instrument  must  be  described,  but  this  can 
be  accomplished  by  merely  naming  the  instrument  and  refer- 
ring to  some  previous  description.  Thus,  it  may  be  stated 
that  a  given  set  of  data  were  obtained  by  means  of  the  U.  S. 
Weather  Bureau  pan,  the  Briggs  and  Shantz  shallow  pan, 
the  Livingston  standard  sphere,  etc.  If  a  new  type  of  in- 
strument has  to  be  used  it  requires  a  complete  description. 

In  stating  the  amount  of  water  lost  from  the  given  instru- 
ments during  a  unit  of  time,  it  is  of  course  unimportant  what 
water  unit  is  employed,  so  long  as  it  is  definite  enough  for  the 
work  in  hand.  Since  the  whole  aim  of  atmometry  is  to  meas- 
ure a  power  to  do  work,  and  since  the  amount  of  liquid  water 
vaporized  per  unit  of  time  is  considered  as  a  measure  of  this 
power,  weight  units  rather  than  volume  units  should  be  used. 
Nevertheless,  if  the  temperature  does  not  vary  too  much,  from 
reading  to  reading,  and  generally  if  there  is  no  need  for  ex- 
treme precision,  volume  units  may  be  used,  and  we  may  con- 
sider that  a  cubic  centimeter  of  water  weighs  a  gram. 

Obviously,  the  volume  or  weight  of  water  lost  from  a  certain 
type  of  instrument  for  a  unit  of  time  may  always  be  multiplied 
by  any  value  that  the  worker  may  like,  so  long  as  this  value 
is  stated,  and  so  long  as  it  is  always  applied  to  all  readings 
from  this  same  type  of  instrument.  This  treatment  does  not 
alter  the  relative  values  of  a  series  of  comparable  readings  and 
the  results  remain  comparable.  This  principle  makes  it  logi- 
cal to  use  depth  units  instead  of  volume  units,  for  free  water 
surfaces,  for  the  depth  of  water  lost  from  a  given  cylindrical 
pan  is  the  volume  lost,  multiplied  by  the  reciprocal  of  the  sur- 
face area,  this  coefficient  being  a  constant  for  the  instrument. 


168  Atmometric   Units  [366 

With  open  pans  it  is  easier  to  measure  depth  than  volume,  for 
rough  approximations.  It  is  true  that  volume  or  weight  read- 
ings from  other  types  of  instrument  than  those  employing  an 
open  pan,  may  also  be  multiplied  by  a  constant  throughout  the 
series,  and  this  constant  might  be  the  area  of  the  surface  em- 
ployed, or  any  other  number  that  may  be  chosen.  But  it  can- 
not be  too  strongly  emphasized  that  such  treatment  is  to  be 
applied  only  to  series  of  readings  that  are  already  comparable, 
and  that  no  constants  can  be  found  by  which  readings  from 
different  types  of  instruments  may  be  rendered  comparable. 

The  use  of  depth  units  in  comparing  water  losses  from  open 
pans  has  introduced  and  supported  a  fallacy  that  is  extremely 
hard  to  combat  in  the  minds  of  those  who  have  not  given  the 
subject  of  atmometry  serious  attention.  This  fallacy  is  based 
upon  the  mistaken  idea  that  the  area  of  the  evaporating  sur- 
face is  the  only  surface  characteristic  that  can  influence  the 
rate  of  evaporation.  If  different  sizes  of  pans  are  employed 
the  readings  are  incomparable,  and  they  remain  incompar- 
able even  after  each  one  has  been  divided  by  the  area  of  its 
own  water  surface.  Eeadings  must  be  stated  as  from  a  cer- 
tain instrument,  in  any  event,  and  the  application  of  an  areal 
coefficient  only  complicates  matters.  To  avoid  the  continua- 
tion of  this  fallacy,  as  much  as  may  be,  it  is  highly  desirable 
that  all  atmometric  readings  be  stated  in  terms  of  weight  or 
volume,  even  though  they  were  originally  obtained  by  measure- 
ments of  depth. 

The  worst  feature  of  the  use  of  depth  units  in  pan  atmome- 
try is  that  it  has  led  to  another  fallacy,  by  which  these  depth 
units  are  taken  to  be  equivalent  to  the  other  depth  units  that 
are  employed  in  the  measurement  of  rainfall.  The  two  classes 
of  units  look  alike  but  they  are  widely  different  in  their  mean- 
ings. An  example  may  illustrate  this  very  important  point. 
Suppose  that  the  rainfall  for  a  certain  place  is  found  to  be 
75  cm.  (of  depth)  for  a  certain  year,  and  suppose  that  the 
observer  states  that  the  evaporation  from  a  Weather  Bureau 
pan  for  the  same  period  was  90  cm.  (also  of  depth).  In  such 
a  case  students  of  climatology  have  been  led  to  say  that  evapo- 


367]  B.  E.  Livingston  169 

ration  exceeds  precipitation  by  a  certain  depth,  15  cm.  in  this 
example.  But  this  means  nothing  at  all ;  if  the  pan  used  had 
been  larger  or  smaller,  of  different  shape  or  material,  or  if  a 
wet  soil  surface  had  been  employed,  etc.,  the  result  would  have 
been  quite  different,  and  the  climatic  conditions  would  surely 
not  have  been  altered  by  merely  changing  the  atmometer.  On 
the  other  hand,  if  any  other  form  or  size  of  raingage  had  been 
employed  the  re-suits  would  be  sensibly  the  same.  The  amount 
of  evaporation  depends  largely  upon  the  atmometer  but  the 
amount  of  rainfall  recorded  is  practically  independent  of  the 
raingage,  so  long  as  the  latter  is  a  raingage  at  all.  It  is  legiti- 
mate to  state  the  index  of  rainfall  in  depth  units,  for  this  is 
not  seriously  influenced  by  the  internal  characteristics  of  the 
gage,  a  statement  that  cannot  be  made  of  the  index  of  evapo- 
ration, nor  even  of  the  index  of  atmospheric  evaporating  pow- 
er. The  only  logical  way  by  which  atmometric  and  precipita- 
tion measurements  may  be  compared  is  by  means  of  their 
ratio,  in  which  case  one  set  of  measurements  may  be  in  depth 
units  and  the  other  in  volume  or  weight  units.  They  are  not 
commensurable  in  any  case,  so  it  is  best  not  to  have  them  even 
appear  as  though  they  were  commensurable.  Other  considera- 
tions, into  which  I  cannot  go  in  this  place,,  lead  unequivocally 
to  the  same  conclusion. 

Fortunately,  there  is  no  serious  difficulty  encountered  in 
the  statement  of  the  time  feature  of  atmometric  measure- 
ments. For  short  periods  the  hour  is  most  convenient,  for 
longer  periods  the  day,  week  and  year  are  all  suitable.  Since 
months  vary  in  length,  monthly  atmometric  indices  are  un- 
satisfactory. After  the  three  features  of  the  unit  to  be  used 
have  been  decided  upon,  it  is  necessary  to  remember  that  at- 
mometric measurements,  like  other  power  measurements,  al- 
ways apply  to  a  certain  set  of  circumstances  and  to  a  certain 
time  period.  The  set  of  circumstances  here  emphasized  is  the 
surroundings  of  the  atmometer,  they  comprise  the  various 
features  of  its  exposure.  The  readings  refer  -to  the  evaporat- 
ing power  of  the  air  only  for  the  particular  location  in  which 
the  instrument  was  operated.  The  evaporating  power  of  the 


170  Vapor  Tension  Deficit  [368 

air  may  be  very  different  in  two  locations  only  a  few  centi- 
meters apart.  The  differences  here  encountered  are  much 
greater  than  the  similar  ones  met  with  in  thermometry  and 
the  general  exposure  of  the  instrument  needs  to  be  stated  in  all 
climatological  studies  of  atmometry.  The  readings  obtained 
are  taken  as  averages  for  the  time  period  of  operation  and  are 
stated  with  reference  to  a  shorter  time  unit. 

To  summarize  the  points  brought  out  above,  every  atmo- 
metric  measurement  should  be  formulated  so  as  to  include  all 
the  five  features  indicated  by  letters  in  the  following  state- 
ment, which  is  given  as  an  illustration.  The  atmometric  in- 
dex for  location  A,  for  the  period  of  operation  E,  is  found  to 
be  G  units  of  water  lost  per  time  unit  D  from  an  atmometer 
of  type  E.  Filling  in  the  features  represented  by  these  let- 
ters, to  render  the  illustration  more  concrete,  we  may  say : 
The  atmometric  index  for  a  place  1  meter  above  the  ground  in 
the  center  of  a  large  field  of  clover  in  northern  Ohio,  for  the 
period  of  operation  from  May  1  to  May  10,  1916,  was  found 
to  be  12  grams  of  water  lost  per  day  from  a  standard  white 
spherical  atmometer.  If  any  of  these  five  features  is  omitted 
from  the  statement,  the  meaning  is  rendered  vague  and  un- 
certain. 


THE  VAPOR  TENSION  DEFICIT  AS  AN  INDEX  OF  THE 
MOISTURE  CONDITION  OF  THE  AIR 

By  BURTON  E.  LIVINGSTON 


Studies  on  the  manner  in  which  external  conditions  con- 
trol the  activities  of  animals  and  plants  must  deal  with  the 
moisture  conditions  of  the  air  in  all  cases  where  the  organ- 
isms considered  are  aerially  exposed.  While  atmospheric 
evaporating  power  (measured  with  reference  to  some  standard 
evaporating  surface)  furnishes  an  index  of  the  air  conditions 
that  influence  the  rate  of  water  loss  from  aerially  exposed 
organisms,  it  is  frequently  desirable  to  analyze  this  complex 


369]  B.  E.  Livingston  171 

condition  into  its  two  components,  the  moisture  condition  of 
the  air  and  the  velocity  of  air  movement  or  circulation.  For 
such  an  analysis  atmometric  observations  are  of  course  inade- 
quate. Furthermore,  it  is  often  requisite  to  compare  different 
evaporating  powers  of  the  air  when  the  air  movement  is 
known  to  be  constant,  in  which  case  the  moisture  condition 
is  the  only  variable  to  be  taken  into  account.  Finally,  in  the 
artificial  control  of  the  air  conditions  of  culture  chambers, 
the  rooms  of  dwellings,  etc.,  it  is  frequently  possible  to  main- 
tain air  circulation  without  much  fluctuation  and  then  to  con- 
trol the  evaporating  power  by  controlling  the  moisture  con- 
dition. In  such  cases  it  becomes  important  that  serious  at- 
tention be  given  to  the  moisture  condition  of  the  air  and  its 
adequate  measurement. 

By  moisture  condition  is  here  meant  that  factor  in  atmos- 
pheric evaporating  power  that  is  independent  of  the  rate  of 
air  movement.  It  is  thus  an  index  of  a  condition  determined 
by  the  state  .of  saturation  of  the  air  (with  aqueous  vapor)  and 
by  the  air  temperature.  Humidity,  as  commonly  measured, 
does  not  involve  temperature.  To  make  these  relations  clearer, 
it  may  be  added  that  the  index  of  atmospheric  evaporating 
power  should  be  equal  to  the  product  of  the  index  of  the  mois- 
ture condition  and  the  index  of  circulation :  /  —  lm  X  Ic, 
Of  course  it  is  here  assumed  that  all  measurements  of  con- 
ditions have  been  properly  weighted  and  brought  into  corre- 
spondence, in  deriving  the  indices.  Otherwise  a  coefficient  of 
proportionality  needs  to  be  applied  to  each  of  the  quantities. 
In  this  equation,  the  value  Im  is  the  one  with  which  this 
discussion  deals. 

The  tendency  of  water  to  evaporate  into  air  lying  next  to 
the  water  surface  is  measured  by  the  maximum  vapor  pressure 
possible  with  the  prevailing  conditions  of  the  surface.  If  pure 
water  is  considered  the  maximum  value  may  be  obtained  for 
any  given  temperature,  from  published  physical  tables.  It 
will  be  lower  than  these  published  values  if  the  water  is  im- 
pure, or  if  it  is  held  by  imbibing  solids,  etc.  It  is  a  gas  pres- 


172  Vapor  Tension  Deficit  [370 

sure,  and  is  expressed  in  pressure  units,  as  the  height  of  a 
mercury  column,  fractions  of  an  atmosphere,  etc.  It  may  be 
considered  as  equal  to  the  pressure  that  drives  the  water  vapor 
out  of  the  liquid  surface,  which  may  be  termed  the  vaporiza- 
tion pressure.  The  temperature  of  the  liquid  lying  close  to 
the  surface  exerts  a  marked  influence  upon  the  magnitude  of 
this  pressure. 

This  tendency  for  water  to  evaporate  is  opposed  by  another 
tendency,  that  of  the  air  'to  deposit  liquid  water  on  the  evapo- 
rating surface ;  it  is  the  tendency  of  water  vapor  to  condense. 
This  is  measured  by  the  partial  pressure  of  water  vapor  in  the 
air  lying  next  to  the  evaporating  surface,  and  it  may  have  any 
value  between  zero  and  the  maximum  vapor  pressure  of  water 
vapor  for  the  given  air  temperature.  It  also  is  a  gas  pressure 
and  is  measured  in  pressure  units.  The  most  satisfactory 
method  of  measuring  it  is  by  means  of  the  Eegnault  dew-point 
apparatus,  through  determining  the  temperature  of  the  dew- 
point,  the  partial  pressure  of  water  vapor  in  the  air  being  equi- 
valent to  the  maximum  vapor  pressure  of  liquid  water  at  the 
temperature  of  the  dew-point  of  the  air.  Another  less  satis- 
factory method  of  determining  this  partial  pressure  is  by 
means  of  the  sling  psychrometer,  the  readings  being  inter- 
preted by  physical  tables  published  for  this  purpose.  .This 
actual  partial  pressure  of  water  vapor  in  the  air  may  be  termed 
the  condensation  pressure. 

From  this  it  follows  that  the  difference  between  the  vapori- 
zation pressure  and  the  condensation  pressure  must  deter- 
mine the  value  of  that  factor  of  atmospheric  evaporating 
power  that  is  not  determined  by  air  circulation.  This  differ- 
ence is  the  vapor  pressure  deficit,  measured  as  a  pressure;  it 
is  the  excess  of  vaporization  pressure  over  condensation  pres- 
sure. For  most  purposes  of  approximation  it  may  be  sup- 
posed that  the  temperature  of  the  liquid  surface  and  that  of 
the  general  air  are  the  same,  but  this  is  not  strictly  true,  and 
the  temperature  value  employed  in  deriving  the  vaporization 
pressure  ought  really  to  be  measured  just  within  the  liquid, 


371]  B.  E.  Livingston  173 

if  the  evaporating  power  of  the  air  for  any  particular  surface 
is  to  be  studied.  The  condensation  pressure  should  be  deter- 
mined for  the  general  atmosphere  of  the  space  under  con- 
sideration. If  air  circulation  were  infinitely  rapid,  which 
means,  practically,  if  there  is  a  high  wind,  this  deficit  value 
should  be  a  measure  of  the  evaporating  power  for  the  particu- 
lar location  considered.  Also,  if  two  sets  of  conditions  are  to 
be  compared,  in  which  the  air  circulation  is  the  same,  then 
the  two  atmospheric  evaporating  powers  'should  be  propor- 
tional to  the  corresponding  vapor  pressure  deficits;  for  the 
other  factor  is  then  common  to  both  sets. 

To  illustrate  the  use  of  the  vapor  pressure  deficit,  let  it  be 
supposed  that  there  are  two  rooms  in  which  the  air  circulation 
is  alike,  and  let  it  be  required  to  estimate  the  relative  values 
of  the  evaporating  powers  corresponding  to  the  two  rooms. 
The  data  involved  and  the  results  obtained  are  shown  below, 
together  with  the  two  relative  humidity  values,  as  usually 
given  in  such  comparisons. 

Air  tern-         VAPOR  PRESSURE        Vapor  pres-        Relative 
perature       Maximum       Actual        sure  deficit          humidity 

deg.  c.         mm.  of  Hg.    mm.  of  Hg.    mm.  of  Hg.         per  cent. 
Room  1.  20°  17.41  14.50  2.91  83 

Room  2.  25°  23.55  6.14  17.41  26 

The  values  used  in  this  example  have  been  so  chosen  that  the 
deficit  for  Eoom  2  is  17.41  mm.,  just  what  it  would  be  for 
Room  1  if  the  actual  vapor  pressure  were  taken  as  zero.  This 
is  the  maximum  deficit  for  a  temperature  of  20°.  Neverthe- 
less, it  is  seen  that  the  actual  vapor  pressure  for  Room  2  is  far 
from  zero.  This  emphasizes  the  point  that  the  maximum 
evaporating  power  of  the  air  increases  with  the  temperature, 
air  pressure,  and  circulation  remaining  the  same. 

Such  comparisons  have  usually  been  made  in  terms  of  rela- 
tive humidity,  the  values  for  which  are  presented  in  the  last 
column  of  the  tabular  arrangement  just  given.  This  mathe- 
matical abstraction  is  the  ratio  of  the  actual  to  the  maximum 


174  Vapor  Tension  Deficit  [372 

vapor  pressure  of  water  vapor  in  the  air,  while  the  vapor  pres- 
sure deficit  is  the  difference  between  these  two  vapor  pressures. 
Eelative  humidity  percentages  are  without  value  unless  the 
air  temperature  is  also  given,  whereas  the  deficit  values  need 
no  reference  to  air  temperature  for  their  interpretation.1  The 
fallacy  in  the  employment  of  relative  humidity  clearly  lies  in 
the  fact  that  its  values  are  ratios  and  that  the  denominator  of 
the  ratio  varies  with  air  temperature;  different  percentage 
values  cannot  .be  comparable  unless  they  are  calculated  to  the 
same  base. 

In  the  illustration  given  above,  the  relative  humidity  index 
for  room  1  is  3.25  times  as  great  as  that  for  room  2,  and  the 
popular  conception  of  relative  humidity  might  lead  to  the 
erroneous  supposition  that  the  evaporating  power  of  the  air 
for  room  2  should  be  3.25  times  as  great  as  that  for  room  1, 
whereas  this  last  number  should  be  the  value  of  the  fraction 

!M!  or  5.98. 
2.91 

The  real  uselessness  of  the  concept  of  relative  humidity  and 
the  manner  in  which  this  concept  is  frequently  misleading 
are  brought  out  by  the  fact  that  the  index  of  relative  humidity 
may  be  identical  for  two  rooms  or  for  two  climatic  stations, 
and  (owing  to  a  difference  in  air  temperature)  the  mois- 
ture factor  of  the  evaporating  power  of  the  air  may  be  very 
different  in  the  two  cases.  Thus,  a  relative  humidity  of  60 
per  cent,  corresponds  to  an  air  moisture  factor  of  10.44  mm. 
at  20°,  and  to  one  of  14.13  mm.  at  25°.  The  moisture  con- 
dition of  the  air  in  the  second  case  is  much  higher,  but  the 
relative  humidity  values  fail  to  suggest  any  difference. 

One  of  the  most  serious  reasons  for  discontinuing  the  use 
of  relative  humidity  lies  in  the  fact  that  the  moisture  con- 
dition of  the  air  generally  varies  from  hour  to  hour  and  from 


1  For  some  very  true  remarks  in  this  connection,  see :  Stevens,  Neil 
E.,  "  A  method  for  studying  the  humidity  relations  of  fungi  in  culture.'1 
Phytopathology  6:  428-432.  1916.  Other  references  are  there  given. 


373]  B.  E.  Livingston  175 

day  to  day,  for  the  same  place,  which  makes  it  necessary  in 
climatic  discussions  to  resort  to  averages  and  means.  While 
the  index  of  relative  humidity  for  any  instant  may  be  readily 
interpreted  by  use  of  the  corresponding  air  temperature.,  there 
is  no  possible  way  by  which  an  average  of  several  such  indices 
may  be  so  interpreted ;  the  average  temperature  for  the  period 
is  of  no  use  for  this  purpose,  since  the  march  of  temperature 
for  the  period  is  not  necessarily  at  all  related  to  that  of  the 
moisture  condition.  The  only  way  to  give  definite  meaning 
to  a  relative  humidity  mean  is  to  obtain  the  original  humidity 
values  from  which  the  mean  was  derived  (together  with  the 
corresponding  air  temperatures),  to  substitute  for  each  indi- 
vidual value  the  corresponding  vapor  pressure  deficit,  and  to 
derive  the  mean  of  the  deficits,  thus  discarding  relative  hu- 
midity altogether. 

For  biological  experimentation,  for  hygienic  studies  of  the 
air  moisture  condition  in  dwellings,  and  for  general  climato- 
logical  purposes,  it  is  very  obvious  that  the  whole  concept  of 
relative  humidity  is  hopelessly  misleading;  the  sooner  this 
concept  can  be  forgotten  the  more  rapidly  will  knowledge  ad- 
vance. When  it  is  not  desirable  or  expedient  to  employ  the 
index  of  atmospheric  evaporating  power  itself  (as  determined 
directly  by  some  form  of  atmometer),  the  moisture  condition 
of  the  air  should  be  stated  in  terms  of  the  vapor  pressure  de- 
ficit, which  demands  no  correction  for  air  temperature  and 
may  represent  evaporating  power  in  all  comparisons  where  the 
index  of  effective  air  circulation  may  be  considered  as  constant. 


176  '  Drying  and  Wilting  of  Plants  [374 


INCIPIENT  DRYING  AND  TEMPORARY  AND  PERMANENT 

WILTING  OF  PLANTS,  AS  RELATED  TO  EXTERNAL 

AND  INTERNAL  CONDITIONS 

By  BURTON  E.  LIVINGSTON 


It  has  been  shown  by  Renner,1  by  Livingston  and  Brown,2 
by  Lloyd 3  and  by  Edith  B.  Shreve,4  that  the  water  content 
of  plant  leaves,  twigs,  etc.,  is  markedly  lower  after  a  period 
of  relatively  great  transpiration  (as  in  the  middle  of  the 
day)  than  it  is  after  a  period  of  very  small  transpiration  (as 
in  the  latter  part  of  the  night).  The  moisture  content  of 
leaves,  for  instance,  was  found  (Livingston  and  Brown)  to 
exhibit  a  diurnal  march,  the  rate  of  water  loss  from  these 
organs  during  the  forenoon  hours  (or  even  during  the 'whole 
period  of  sunshine)  being  greater  than  their  rate  of  water 
intake,  while  the  rate  of  foliar  intake  of  water  during  the 
night  hours  was  greater  than  the  rate  of  water  loss.  "  The  phe- 
nomenon indicated  by  diminished  water  content  in  the  day- 
time was  called  incipient  drying  by  Livingston  and  Brown. 
Renner  employed  the  term  sdtigungsdefizit  to  denote  the 
similar  phenomenon  encountered  in  his  experiments.  The 
experimentation  of  all  but  Renner,  of  the  authors  mentioned 


1  Renner,  0.,  "  Experimentelle  Beitrage  zur  Kenntnis  der  Wasser- 
bewegung."     Flora  103:   171-247.     1911.     Idem.,  "  Versuche  zur  Me- 
chanik  der  Wasserversorgung.     I.  Der  Druck  in  den  Leitungsbahnen 
von  Freilandpflanzen.     Ber.  Deutsch.  Bot.  Ges.  30:  576-580.     1912. 

2  Livingston,   B.   E.,   and  Brown,   W.   H.,   "  Relation   of  the   daily 
march  of  transpiration  to  variations  in  the  water  content  of  foliage 
leaves."    Bot.  Gas;.  53:  309-330.     1912. 

3  Lloyd,  F.  E.,  "  The  relation  of  transpiration  and  stomatal  move- 
ments to  the  water  content  of  the  leaves  of  Fonquieria  splendens." 
Plant   World    15:    1-14.     1912.     Idem.,    "Leaf   water    and   stomatal 
movement  in  Gossypium,  and  a  method  of  direct  visual  observation 
of  stomata  in  situ.     Bull.  Torrey  Bot.  Club  40:  1-26.     1913. 

4  Shreve,  Edith  B.,  "  The  daily  march  of  transpiration  in  a  desert 
perennial."     Carnegie  Inst.  Wash.  Pub.    194:    Washington,   1914. 


375]  B.  E.  Livingston  177 

above,  was  carried  out  in  an  arid  region,  with  high  transpira- 
tion rates,  but  the  results  of  Renner  were  obtained  in  a  very 
moist  summer  in  Munich,  so  that  it  appears  to  be  fairly  well 
established  that  this  phenomenon  is  general  in  plants.  Of 
course,  incipient  drying  is  more  pronounced  with  high  atmos- 
pheric evaporating  power  and  intense  sunshine  than  with 
aerial  surroundings  of  less  aridity,  and  it  is  less  pronounced 
in  plants  with  low  transpiring  power  than  it  is  in  less  xero- 
philous  forms. 

From  Eenner's  experiments,  and  also  from  those  of  Living- 
ston and  Hawkins,5  it  appears  that  the  rate  of  absorption  of 
water  by  plant  roots  is  determined  by  two  conditions,  which 
may  be  called,  respectively,  the  absorbing  power  of  the  roots 
(internal)  and  the  supplying  power  of  the  soil,  or  other 
medium  in  which  the  roots  lie  (external).  It  also  appears 
that  the  internal  one  of  these  conditions  (absorbing  power  of 
the  roots)  is  at  least  partly  controlled  by  the  degree  of  incipi- 
ent drying  occurring  in  the  plant,  which,  in  turn  is  partly 
dependent  upon  the  rate  of  transpiration.  Other  conditions 
being  unchanged,  the  plant  takes  up  more  water  from  the 
soil  when  the  transpiration  rate  is  high  than  when  it  is 
lower.  If  incipient  drying  becomes  sufficiently  pronounced 
its  presence  is  made  evident,  first  by  loss  of  turgor  in  the 
plant,  then  by  temporary  wilting6  (from  which  the  wilted 
tissues  may  recover  when  transpiration  is  subsequently  de- 
creased), then  by  permanent  wilting7  (from  which  the  plants 

5 Livingston,  B.  E.,  and  Hawkins,  Lon  A.,  "The  water  relation 
between  plant  and  soil."  Carnegie  Inst.  W\ash.  Pub.  204:  5-48. 
Washington,  1915. 

6  Brown,  W.  H.,  "  The  relation  of  evaporation  to  the  water  content 
of  the  soil  at  the  time  of  wilting."  Plant  World  15:  121-134.  1912. 

7Briggs,  L.  J.,  and  Shantz,  H.  L.,  "The  wilting  coefficient  for 
different  plants  and  its  indirect  determination.  U.  S.  Dept".  Agric. 
Bur.  Plant  Ind.  Bull.  230:  1912.  Caldwell,  J.  S.,  "The  relation  of 
environmental  conditions  to  the  phenomenon  of  permanent  wilting  in 
plants.  Physiol.  Res.  1 :  1-56.  1913.  Shive,  J.  W.,  and  Living- 
ston, B.  E.,  "  The  relation  of  atmospheric  evaporating  power  to 
soil  moisture  content  at  permanent  wilting  in  plants.  Plant  World 
17:  81-121.  1914.  . 


178  Drying  and  Wilting  of  Plants  [376 

cannot  recover  without  special  treatment),  and  finally  by 
death  and  actual  desiccation. 

Incipient  drying  of  leaves,  whether  they  show  any  signs 
of  wilting  or  not,  may  be  said  to  be  due  to  inadequate  water 
supply  to  these  organs;  no  matter  how  great  might  be  the 
rate  of  foliar  water  loss,  the  transpiring  cells  should  not  suf- 
fer any  diminution  in  their  water  content  if  the  rate  of 
entrance  of  water  into  these  cells  were  only  sufficiently  great. 
The  question  therefore  arises,  as  was  mentioned  by  Living- 
ston and  Hawkins,  to  what  extent  is  this  inadequacy  in  the 
rate  of  foliar  water  supply  to  be  considered  as  due  to  inade- 
quate water  supplying  power,  of  the  soil,  and  to  what  extent 
may  it  be  due  to  inadequate  absorbing  power  of  the  roots  and 
inadequate  conducting  power  of  the  stems,  petioles,  etc.  ?  In 
wilting  leaves,  for  example,  is  the  insufficient  rate  of  water 
supply  due  to  an  external  condition  in  the  soil  or  to  an  inter- 
nal condition,  within  the  plant  body? 

This  is  a  very  important  question,  both  with  regard  to  the 
general  problem  of  plant  water  relations  and  with  respect  to 
the  practical  problem  of  drought  resistance  in  plants.  A 
quantitative  answer  for  plants  growing  in  the  open  is  of 
course  impossible  at  present,  but  some  light  has  been  thrown 
upon  the  consideration  of  this  question  by  some  experiments 
recently  carried  out  in  the  Laboratory  of  Plant  Physiology.8 
The  matter  in  hand  was  approached  by  making  the  water- 
supplying  power  of  the  root  surroundings  very  great ;  the  test 
plants  were  grown  in  water-culture  instead  of  in  soil,  so  that 
the  external  resistance  offered  to  water  absorption  by  the  root 
surfaces  may  be  considered  as  practically  nil  and  therefore 
constant.  Under  such  conditions  the  actual  rate  of  water 
absorption  must  be  very  nearly  proportional  to  the  absorbing 
power^of  the  root  system. 

Two  methods  were  employed,  for  both  of  which  the  tran- 
spirational  rates  were  determined  by  weighing,  in  the  ordi- 


8  Mr.    E.    S.    Johnston    carried    out    the    manipulations    in    these 
experiments. 


377]  B.  E.  Livingston  179 

nary  way.  By  one  method  the  absorption  rates  were  deter- 
mined as  volumes,  the  plant  being  sealed  into  a  bottle  com- 
pletely filled  with  the  nutrient  solution  arid  furnished  with  a 
burette  for  measuring  the  volume  of  water  absorbed.  Tem- 
perature changes  were  corrected  for  by  means  of  readings 
taken  from  a  similar  arrangement  of  bottle  and  burette  with- 
out any  plant.  By  the  other  method  arrangement  was  made 
by  which  the  plant  could  be  suspended  from  the  balance  arm, 
its  roots  in  the  culture  solution,  with  the  surface  of  the  latter 
always  at  the  same  mark  on  the  basal  part  of  the  stem  when 
the  balance  was  in  equilibrium.  Thus,  the  buoyancy  tending 
to  lift  the  plant  was  very  nearly  the  same  at  all  weighings. 
During  this  weighing  the  split  cork  otherwise  closing  the  cul- 
ture jar  was  removed.  Observations  were  obtained  usually 
at  hour  intervals,  from  before  daylight  in  the  morning  to  late 
in  the  evening.  The  plants  used  were :  Coleus  blumei,  Fago- 
pyrum  esculentum  (buckwheat)  and  Mimosa  pudica  (sensi- 
tive plant).  The  experiments  were  carried  out  in  an  experi- 
ment greenhouse,  in  the  autumn  and  early  winter.  The 
nutrient  solution  employed  was  of  the  Shive  3-salt  type, 
apparently  physiologically  balanced  as  to  salt  proportions, 
and  its  total  osmotic  concentration  was  about  1.75  atmos- 
pheres. The  results  of  eight  tests,  at  different  times  of  the 
year,  may  be  briefly  stated  as  follows. 

(1)  Sept.    20,    clear    sky.     Buckwheat    plant.     Transpiration    was 
greater  than  absorption   for  the  period  8:50   a.   m.   to   1:50  p.  m., 
incipient  drying  amounting  to  0.63  g.     Absorption  was  greater  than 
transpiration  for  the  period  1:50  to  5:50  p.  m.,  the  plant  gaming  in 
weight  0.15  g.     Wilting  began  during  hour  ending  10:50  a.  m.,  when 
incipient  drying  amounted  to  0.27   g.     Transpiration   for  this  hour 
was  0.81  g.  and  absorption  was  0.59  g.    Transpiration  for  last  hour  of 
incipient  drying  was  0.98  g.  and  absorption  was  0.96  g.     Five  out  of 
six  leaves  were  permanently  wilted  and  never  recovered. 

(2)  Sept.    21,    clear    sky.     Buckwheat    plant.     Transpiration    was 
greater  than  absorption   for  the  period   9:20  a.  m.  to   1:20  p.   m., 
incipient  drying  amounting  to  0.24  g.     Absorption  was  greater  than 
transpiration  for  the  period  1:20  to  9:20  p.  m.,  the  plant  gaining 
in  weight  0.38  g.     Wilting  began  during  hour  ending   10:20  a.  m., 
when  incipient  drying  amounted  to  0.08  g.     For  this  hour  transpira- 


180  Drying  and  Wilting  of  Plants  [378 

tion  was  1.36  g.  and  absorption  was  1.28  g.  Transpiration  for  the 
last  hour  of  incipient  drying  was  1.26  g.  and  absorption  was  1.18  g. 
No  permanent  wilting  occurred. 

(3)  Sept.    23,    cloudy   or    partly    cloudy.    Buckwheat   plant.    Ab- 
sorption was  greater  than  transpiration  for  the  period  6:50  to  7:20 
a.  m.,  the  plant  gaining  0.03  g.     Transpiration  and  absorption  were 
equal  (0.08  g.)  for  the  period  7:20  to  7:50  a.  m.     Transpiration  was 
greater  than  absorption  for  the  period  7:50  a.  m.  to  2:20  p.  m.,  incipi- 
ent drying  amounting  to  0.59  g.     Wilting  began  during  hour  ending 
10.20,   when   incipient   drying   amounted   to   0.33   g.     Transpiration 
for  this  hour  was  0.56  g.  and  absorption  was  0.44  g.     Transpiration 
and  absorption  for  the  period  of  incipient  drying  (7.50  to  9.20  a.m.) 
were  0.67  and  0.46  g.;  for  the  last  period  of  incipient  drying  (12.30 
to  2.20  p.m.)   they  were  1.49  and  1.43  g.,  respectively.      Three  out 
of  five  leaves  were  permanently  wilted  and  never  recovered. 

(4)  Nov.  3,  clear  sky.    Dark  red  Coleus  plant.     Transpiration  and 
absorption  were   equal    (0.29  g.)    for   the  hour   7:30  to   8:30  a.  m. 
Transpiration  was  greater  for  the  period  8:30  to  11:30  a.  m.,  incipi- 
ent drying  amounting  to  0.35  g.    Absorption  was  greater   for  the 
period  11:30  a.  m.  to  7:30  p.  m.,  the  plant  gaining  in  weight  0.68  g. 
Transpiration  and  absorption  were  equal    (0.16  g.)    for  the  period 
7:30  to  9:30  p.  m.     No  wilting  was  noted.     The  evaporating  power 
of  the   air  was   1.02  cc.    (per  hour,  from   the   Livingston   standard 
white  spherical  atmometer)    for  the  first  hour  of  incipient  drying. 
Transpiration  for  this  hour  was  0.76  g.  and  absorption  was  0.70  g. 

(5)  Nov.   4,   cloudy.     Dark  red   Coleus  plant.     Transpiration   and 
absorption  were  equal    (0.11  g.)    for  the  period  5:30  to  7:30  a.  m. 
Transpiration  was  greater  for  the  period  7:30  a.  m.  to  2:30  p.  m., 
incipient  drying  amounting  to  0.47  g.    Absorption  was  greater  for 
the  period  2:30  to  5:30  p.  m.,  the  plant  gaining  in  weight  0.10  g. 
No   wilting   was   noted.     The    atmometric   index   for    first   hour   of 
incipient  drying  was  0.33  cc.     Transpiration  for  this  hour  was  0.10 
g.   and  absorption  was   0.01   g. 

(6)  Nov.   16,   clear   sky.     Two  buckwheat   plants  bound   together 
at  base.     Transpiration  was  greater  than  absorption  for  the  period 
9:30  to  11:30  a.  m.,  incipient  drying  amounting  to  0.17  g.     Absorp- 
tion was  greater  for  the  period  11:30  a.  m.  to  10:30  p.  m.,  the  plants 
gaining  in  weight  0.33  g.     No  wilting  was  noted.     Atmometric  index 
for  last  hour  of  incipient  drying  was  0.9  cc.     Transpiration  for  this 
hour  was  1.83  g.  and  absorption  was  1.79  g. 

(7)  Nov.    16,   clear   sky.     Dark   red   Coleus    plant.     Transpiration 
was  greater  than  absorption  for  the  period  9:45  a.  m.  to  3:45  p.  m., 
incipient  drying  amounting  to  0.89  g.     Absorption  was  greater  than 
transpiration  for  the  period  3:45  to  7:45  p.  m.,  the  plant  gaining 
in  weight   0.78  g.    No  wilting  was   noted.     The  atmometric  index 


379]  B.  E.  Livingston  181 

for  last  hour  of  incipient  drying  was  1.3  cc.     Transpiration  for  this 
hour  was  0.38  g.,  and  absorption  was  0.11  cc. 

(8)  Dec.  1,  cloudy.  Mimosa  plant.  Transpiration  was  greater 
than  absorption  for  the  period  7:55  a.  m.  to  3:55  p.  m.,  incipient 
drying  amounting  to  2.97  g.  Absorption  was  greater  than  tran- 
spiration for  the  period  3:55  to  5:55  p.  m.,  the  plant  gaming  in 
weight  0.27  g.  No  wilting  was  noted;  the  leaves  were  in  night 
position  at  end  of  last  hour.  Atmometric  index  for  last  hour  of 
incipient  drying  was  0.7  cc.  Transpiration  for  this  hour  was  1.03  g. 
and  absorption  was  0.87  cc. 

These  data  show  very  clearly  that  incipient  drying,  tempo- 
rary wilting,  and  even  permanent  wilting  of  most  of  the 
leaves,  may  occur  without  any  resistance  at  all  to  water- 
absorption  by  roots.  These  phenomena  are  here  quite  inde- 
pendent of  such  resistance  to  water  intake  as  may  be  offered 
by  unsaturated  soils.  Furthermore,  in  the  complete  absence 
of  environmental  resistance  to  water  absorption  by  the  root 
system,  incipient  drying  may  begin  with  an  evaporating 
power  of  the  air  as  low  as  0.33  cc.  per  hour  from  the  Living- 
ston standard  white  sphere  (Coleus,  Nov.  4).  Consequently, 
it  does  not  require  a  high  atmometric  index  to  render  the 
transpiration  rate  larger  than  the  rate  of  absorption,  in  the 
case  of  some  plants  at  least.  The  truth  of  this  statement  must 
be  much  more  pronounced  when  the  plant  roots  are  sur- 
rounded by  ordinary,  fairly  dry  soils,  which  interpose  an  ex- 
ternal resistance  to  water  intake. 

Unfortunately,  atmometric  observations  were  omitted  in 
the  first  three  tests,  so  that  it  is  not  possible  to  state  what 
order  of  atmometric  index  values  produced  the  wilting  phe- 
nomena recorded  for  Sept.  20,  21  and  23.  It  is,  of  course, 
certain  that  these  index  values  were  not  exceptionally  high, 
however;  the  index  for  Baltimore  is  never  high,  and  there 
\vas  no  artificial  heat  applied  to  the  greenhouse  on  these 
days,  so  that  the  index  value  was  not  artificially  raised.  It 
is  worth  something  to  note  that  permanent  wilting  of  most 
of  the  leaves  of  healthy  buckwheat  plants  occurred  in  an 
unheated  greenhouse  in  Baltimore  on  Sept.  20,  with  clear  sky, 
and  on  Sept.  23,  with  partly  cloudy  sky. 


182  Deficient  Soil  Oxygen  [380 

Obviously,  the  absorbing  powers  of  these  plants  were  inade- 
quate to  supply  water  as  rapidly  as  it  was  lost  by  transpira- 
tion during  the  hours  when  this  loss  was  most  rapid;  the 
inadequacy  was  within  the  plant,  an  internal  condition.  It 
is  suggested  that  the  power  of  stem  and  petioles  to  conduct 
water  from  roots  to  leaves  is  here  also  inadequate,  but  on 
this  point  further  experimentation  will  be  required. 

One  definite  advance  in  our  knowledge  of  the  water  rela- 
tions of  plants  is  made  by  the  data  here  considered;  it  may 
now  be  clearly  stated  that  none  of  these  three  stages  or  de- 
grees of  incipient  drying  need  necessarily  be  related  to  soil-, 
moisture  conditions  at  all.  That  they  may  sometimes  be  so 
related,  when  the  soil  about  the  root  system  fails  to  supply 
moisture  to  the  root  surfaces  as  rapidly  as  these  are  able 
to  absorb  it,  is  sufficiently  clear  on  a  priori  grounds. 


THE  EFFECT  OF  DEFICIENT  SOIL  OXYGEN  ON  THE 
ROOTS  OF  HIGHER  PLANTS 

By  B.  E.  LIVINGSTON  AND  E.  E.  FREE 


During  the  last  three  years  experiments  have  been  in 
progress  in  the  Laboratory  of  Plant  Physiology  on  the  oxy- 
gen requirement  of  the  root  systems  of  higher  plants.  A 
technique  has  been  devised  by  which  the  root  system,  con- 
tained in  normal  soil,  can  be  sealed  off  from  the  air  and  th- 
soil  atmosphere  controlled  in  composition  as  may  be  desirecL 
The  aerial  portions  of  the  plants  project  into  the  atmosphere 
of  the  greenhouse.  Water  is  supplied  to  the  roots  by  means 
of  the  Livingston  auto-irrigator.1  It  has  been  found  that 


1  Livingston,  B.  E.,  "  A  method  for  controlling  plant  moisture." 
Plant  World  1 1 :  39-40.  1908.  Hawkins,  Lon  A.,  "  The  porous  clay 
cup  for  the  automatic  watering  of  plants."  Plant  World  13:  220-227. 
1910.  Livingston,  B.  E.,  and  Hawkins,  Lon  A.,  "The  water-relation 
between  plant  and  soil."  Carnegie  Inst.  Wash.  Pub.  204:  5-48.  1915. 


381]  B.  E.  Livingston  and  E.  E.  Free  183 

the  response  of  the  root-system  to  deficiency  of  oxygen  in 
the  soil  atmosphere  varies  widely  in  different  kinds  of  plants. 
Some  species  are  injured  by  a  very  slight  deficiency  below 
the  oxygen  content  of  the  general  atmosphere.  A  swamp 
willow,  probably  Salix  nigra,  endures  successfully  the  com- 
plete, or  almost  complete,  exclusion  of  oxygen  from  its  roots. 
In  the  case  of  those  plants  which  are  injured  by  deficient 
soil  oxygen  it  is  interesting  physiologically  that  the  first 
effect  of  oxygen  deprivation  is  an  interference  with  the  ab- 
sorption of  water  by  the  roots.  In  the  experiments  the 
apparatus  for  the  supply  of  water  is  so  arranged  that  the 
amount  of  water  taken  up  by  the  soil  from  the  porous  cups 
of  the  auto-irrigator  can  be  measured  for  periods  as  short 
as  one  hour.  The  amount  of  water  thus  taken  up  depends 
in  part  on  the  temperature.  The  surface  tension  of  the 
water  films  in  the  soil  varies  with  temperature  and  this  con- 
trols the  amount  of  water  held  in  the  water-film  system. 
However,  this  error  disappears  for  periods  the  initial  and 
final  temperatures  of  which  are  nearly  the  same  (for  in- 
stance, the  usual  24-hour  period)  and  a  correction  can  be 
made  for  the  error  in  the  case  of  shorter  periods  or  other 
periods  which  do  not  satisfy  this  condition.  When  the  tem- 
perature error  is  thus  eliminated,  the  absorption  of  water 
from  the  auto-irrigator  is  closely  parallel  to  the  intake  of 
water  by  the  plant  roots.  With  the  plants  that  are  sensi- 
tive to  deficiency  of  oxygen  in  the  soil  air,  it  is  found  that 
the  replacement  of  the  normal  soil  atmosphere  by  nitrogen 
is  followed  within  a  few  hours  by  nearly  complete  cessation 
of  water-intake  by  the  roots.  With  the  most  sensitive  species 
tested,  namely,  Coleus  blumei  and  ffeliotropium  peruvianum, 
this  cessation  of  water-intake  occurs  always  within  24  hours, 
usually  within  12  hours,  after  the  soil  oxygen  is  removed. 
This  time  period  varies  with  the  individual  plant,  perhaps 
because  of  differences  in  the  root-system  but  probably  also 
because  of  differences  in  the  completeness  with  which  the 
soil  oxygen  originally  present  is  replaced  by  the  nitrogen. 
Since  the  oxygen  must  be  displaced  by  washing  out  with 


184  Deficient  Soil  Oxygen  [382 

the  nitrogen  it  is  impossible  to  be  sure  that  the  replacement 
is  ever  absolutely  complete  at  the  beginning  of  the  experi- 
ment. 

The  cessation  of  water  intake,  as  shown  by  the  stoppage 
^of  absorption  from  the  auto-irrigator,  is  always  the  first 
sign  of  injury.  With  Coleus  and  Heliotr  opium  it  is  followed 
in  from  one  to  six  days  by  progressively  lessened  turgor  of 
the  shoot  and  leaves  and  finally  by  wilting  and  death.  With 
Coleus,  the  admission  of  oxygen  to  the  soil  before  death  has 
actually  occurred  is  followed  by  the  slow  recovery  of  the 
plant.  Heliotropium  does  not  so  recover,  even  if  oxygen  is 
re-supplied  before  the  wilting  has  become  extensive  or 
severe.  With  Nerium  oleander,  which  does  not  wilt,  the 
symptom  of  injury  which  follows  next  after  the  cessation 
of  water  intake  by  the  roots  is  the  yellowing  and  loss  of 
leaves. 

On  removal  and  examination  of  the  injured  plants  the 
root  systems  are  found  to  be  dead  and  the  roots  partly  dis- 
integrated. When  the  injury  has  been  slight  or  recent,  in- 
dividual roots  are  determinately  dead  only  in  parts  of  their 
length,  regions  of  brown  discoloration  alternating  with  re- 
gions of  apparently  healthy  root.  When  Coleus  is  first  in- 
jured and  then  revived  by  re-admission  of  oxygen  it  forms 
a  new  root  system,  the  new  healthy  roots  being  clearly  dis- 
tinguishable from  the  older  dead  ones.  These  new  roots  start 
always  from  the  base  of  the  stem,  as  in  a  rooted  cutting. 
They  have  never  been  observed  to  start  from  any  portion 
of  the  older  root  system.  If  one  begins  with  a  Coleus  plant 
which  has  a  small  root  system,  or  with  an  unrooted  cutting, 
or  with  a  previously  injured  plant  which  will  form  new 
roots,  it  is  possible  to  grow  such  a  plant  with  a  soil  atmos- 
phere somewhat  below  normal  in  oxygen  content.  In  this 
case  the  shoot  does  not  attain  so  large  a  size  as  the  shoot 
of  a  normal  control  plant  and  is  more  susceptible  to  injury 
by  drouth,  as,  for  instance,  by  increase  in  the  evaporating 
power  of  the  air.  The  root  system  of  such  a  plant,  grown 
with  deficient  oxygen,  is  less  developed  than  that  of  a  normal 


383]  B.  E.  Livingston  and  E.  E.  Free  185 

plant  and  the  roots  are  long,  thin  and  little  branched,  and 
range  widely  through  the  soil. 

When  Coleus  plants  of  different  sizes  are  deprived  of  soil 
oxygen,  the  cessation  of  water  intake  and  the  subsequent 
symptoms  of  injury  appear  first  and  are  most  severe  on 
the  plants  which  have  the  larger  root  systems.  Again,  a 
plant  with  a  small  root  system  will  tolerate  a  lesser  oxygen 
content  in  the  soil  than  will  a  plant  with  a  large  root  system. 
This  implies  that  the  crucial  matter  is  the  supply  of  oxygen 
per  unit  of  root  surface  (or  volume)  and  this  is  confirmed 
by  the  fact  that  a  low  oxygen  content  in  a  frequently  changed 
atmosphere  is  less  injurious  than  a  higher  oxygen  content 
with  less  frequent  changes. 

The  evidence  suggests  that  the  cause  of  injury  by  exclu- 
sion of  oxygen  from  the  roots  is  an  interference  with  the 
respiration  of  the  protoplasm  of  the  root  cells,  resulting  in 
the  death  of  this  protoplasm  and  the  consequent  failure 
of  the  roots  to  function  as  water  absorbers  for  the  plant. 
There  is  no  reason,  however,  to  assume  any  "vital"  func- 
tion of  the  root  protoplasm  in  promoting  water  absorption. 
The  protoplasmic  coagulation  which  is,  or  accompanies, 
what  is  called  death  would  constitute  in  itself  a  sufficient 
change  to  explain,  on  a  purely  physical  basis,  this  effect  on 
water  absorption.  The  fact  that  the  roots  of  at  'least  one 
plant  (Salix)  appear  to  function  normally  in  the  absence 
of  free  oxygen  raises  the  interesting  question  whether  the 
respiration  of  these  roots  may  not  be  anaerobic.  It  is  im- 
ppssible  to  answer  this  question  finally.  There  is  a  theoret- 
ical possibility,  in  our  experiments,  of  some  small  access  of 
free  oxygen  from  some  source  not  now  suspected.  However, 
the  sharp  difference  in  the  behavior  of  Salix  and  of  Coleus 
under  identical  treatments  suggests  some  important  differ- 
ence in  the  respiratory  habits  of  the  roots  of  the  two  species. 


186  Soil-Moisture  Minimum  [384 


THE  EXPERIMENTAL  DETERMINATION  OF  A  DYNAMIC 
SOIL-MOISTURE  MINIMUM 

By  HOWARD  E.  PULLING 


The  conditions  determining  the  rates  of  water  movement 
in  soils  have  long  been  recognized  as  of  great  importance 
in  plant  physiology,  since  they  not  only  limit  the  amount 
of  water  a  given  root  system  may  receive  but  also  modify 
the  effects  of  all  soil  processes  upon  rooted  plants.  In  aerated 
soils  water  is  moved  by  surface  forces  of  the  soil-moisture 
films.  The  magnitude  of  these  forces  is  dependent  upon  the 
curvature  of  the  film-air  surfaces  and  not  upon  the  amount 
of  water  in  the  soil,  so  that  a  soil  volume  might  augment 
its  water  content  at  the  expense  of  another  contiguous  soil 
volume  that  contained  actually  less  water  than  the  first. 
The  amount  of  water  that  may  be  moved  in  unit  time  de- 
pends, however,  also  upon  the  amount  of  water  in  the  films 
and  a  certain  minimum  should  exist  below  which  the  quan- 
tity of  water  subject  to  capillary  movement  is  too  small  to 
admit  of  any  but  negligible  rates,  regardless  of  the  mag- 
nitude of  the  surface  forces. 

In  aerated  soils  the  water  that  responds  to  surface  tension 
urge  is  accumulated  around  the  points  of  contact  of  soil 
grains,  so  that  the  water  adsorbed  upon  the  surface  of  the 
grains,  imbibed  by  the  soil  colloids  and  held  as  water  of 
hydration  by  the  grain  constituents  need  not  be  considered 
in  the  present  discussion.  It  is  apparent  that  the  greater 
the  number  of  such  points  of  contact  between  the  soil  grains 
in  a  given  gross  volume  of  soil,  the  greater  should  be  the 
number  of  similar  capillary  masses  of  water  and,  conse- 
quently, the  greater  should  be  the  amount  of  water  in  the 
soil  when  the  rate  of  capillary  movement  becomes  negligible. 
Accordingly  a  complete  statement  of  this  minimum  for  any 
soil  may  be  represented  not  by  a  point  but  by  a  curve,  in 


385]  H.  E.  Pulling  1ST 

which  the  conditions  of  the  soil-air-water  system  are  repre- 
sented in  terms  of  any  two  of  the  three  components. 

For  convenience  the  components  soil  grains  and  water  may 
be  selected.  The  number  of  points  of  contact  in  any  gross 
volume  are  determined  by  the  number,  size,  shape  and  ar- 
rangement of  the  soil  grains.  In  a  sufficiently  large  volume 
(a  few  cubic  centimeters,  for  arable  soils)  the  soil  grains 
may  be  considered  as  possessing  an  average  density,  size 
and  shape,  and  this  average  will  not  change  when  other 
samples  of  the  same  soil  are  considered.  Likewise  if  two 
samples  of  the  same  volume  have  the  same  number  of  soil 
grains,  possessing  the  same  average  characteristics,  it  may 
be  assumed  that  the  average  arrangement  of  grains  is  the 
same  in  each.  This  will  be  the  more  strictly  true  the  longer 
the  grains  have  existed  in  those  volumes,  since  the  forces 
of  surface  tension  and  gravity  will  tend  to  place  them  in 
the  most  stable  positions.  A  relative  measure  of  the  proper- 
ties of  a  mass  of  soil  grains  may  thus  be  obtained  for  any 
one  soil  in  terms  of  its  dry  weight  per  unit  of  gross  volume, 
termed  the  packing. 

The  properties  of  the  water  masses  in  the  soil  may  also  be 
considered  as  being  of  average  character  and  since  these  prop- 
erties depend  upon  the  shape  and  size  of  the  water  masses, 
which  in  turn  depend  upon  the  shape  and  size  of  the  spaces 
about  the  points  of  contact  of  the  soil  grains,  the  number 
of  these  points  and  the  amount  of  water  in  the  soil,  they 
will  be  sufficiently  defined  by  the  amount  of  water  and  the 
amount  of  soil  contained  in  each  unit  of  gross  volume.  When 
these  amounts  are  determined  for  samples  of  any  given  soil, 
each  uniformly  packed  and  permitting  only  a  negligible  rate 
of  water  movement,  the  data  are  at  hand  for  plotting  the 
experimental  approximation  to  the  minimum  moisture  curve 
between  the  limits  of  packing  encountered  in  the  samples. 

A  method  has  been  devised  by  the  use  of  which  samples 
of  any  given  soil,  each  of  approximately  uniform  packing, 
may  be  obtained  with  water  contents  so  small  that  the  rate 
of  water  movement  is  about  0.001  gram  in  24  hours  through 


188  Sub-Artie  Soil  [386 

an  area  of  30  square  millimeters.  If  the  water  contents  per 
unit  of  gross  volume  of  a  number  of  such  samples  of  the 
same  soil  are  plotted  as  ordinates,  and  the  corresponding  dry 
weights  are  plotted  as  abscissas,  the  graph  obtained  by  con- 
necting the  points  is  the  positive  portion  of  an  approximately 
paraboliform  curve  that  is  symmetrical  about  the  horizontal 
axis.  This  graph  ascends  steeply  in  the  region  of  light  pack- 
ings, indicating  the  relatively  large  effect  of  adding  more 
soil  to  a  volume  of  low  soil  content.  Its  tendency  to  become 
horizontal  indicates  that,  with  dense  packings,  the  addition 
of  more  soil  but  slightly  increases  the  water  content  at  the 
dynamic  minimum. 

The  amount  of  water  that  exists  in  a  given  soil  at  a  given 
packing  above  the  minimum  point  for  that  packing  is  sub- 
ject to  capillary  movement,  so  that  the  determination  of  the 
minimum  is  of  great  value  in  calculating  the  maximum  rate 
at  which  water  may  move  through  the  given  soil  under  those 
conditions.  Because  the  graphs  vary  in  height  and  slope, 
at  corresponding  points,  from  one  soil  to  another  they  should 
also  serve  as  soil  characteristics  by  which  various  soils  might 
be  recognized. 


SOME   UNUSUAL   FEATURES   OF  A  SUB-ARCTIC   SOIL 

By  HOWARD  E.  PULLING 


A  preliminary  survey  of  the  ecological  features  of  some 
sub-arctic  forests  during  the  past  summer  yielded  informa- 
tion concerning  the  soils  that  emphasizes  the  need  of  in- 
cluding the  physical  root -environment  in  an  ecological  study 
of  such  regions.  The  chief  soil  over  the  major  portion  of 
the  area  visited1  was  a  gray  to  buff  colored  lacustrine  clay 


1The  valleys  of  the  Nelson  river  and  its  tributaries  near  Split 
Lake,  which  is  situated  in  northern  Manitoba,  Canada,  at  about  56  o 
north  latitude  and  96°  west  longitude. 


387]  H.  E.  Pulling  189 

formed  from  rock  flour  in  the  bed  of  ancient  lake  Aggasiz. 
The  upper  limit  of  frozen  soil  encountered  during  the  sum- 
mer varied  from  a  depth  of  a  few  inches,  near  the  water's 
edge  on  a  shore  with  a  north  exposure,  to  about  six  feet  on 
a  slope  well  above  the  water  line  and  with  a  southeast  ex- 
posure. It  is  highly  probable  that  one  of  the  most  effective 
agencies  conditioning  local  distribution  of  plant  species  is 
the  depth  at  which  frozen  soil  is  encountered.  Large  trees 
and  other  deeply  rooted  plants  could  not  exist  in  soils  made 
too  shallow  by  the  presence  of  perpetually  frozen  soil  near 
the  surface. 

The  soil  of  the  spruce  forest,  which  is  the  characteristic 
type  of  this  region,  is  covered  chiefly  by  sphagnum,  often  to 
a  depth  of  several  feet.  Large  amounts  of  water  are  held 
by  the  moss  so  that  these  forests  resemble  those  of  temperate 
regions  at  the  borders  of  swamps  and  marshes.  If  the  forest 
is  situated  on  a  hillside,  however,  the  soil  underneath  the 
moss  is  usually  dry  and  if  exposed  in  windy  weather  will 
blow  as  dust.  This  may  perhaps  be  explained  in  the  light 
of  knowledge  of  the  conditions  above  and  below  the  dry 
layer.  This  dry  stratum  rests  upon  frozen  soil,  which  be- 
cause of  its  lower  vapor  pressure  and  of  other  probably  less 
effective  properties,  should  continually  absorb  water  from 
the  adjacent,  unfrozen  soil.  Thus,  making-the  easily  justified 
assumption  that  the  soil  was  originally  wet,  the  conditions 
exist  for  almost  completely  drying  it,  provided  it  should  not 
regain  the  water  lost.  The  light  snowfall  in  this  region 
would  be  unlikely  to  produce  large  amounts  of  water  in  the 
spring,  especially  on  these  slopes  where  drainage  in  the  spring 
is  rapid  over  the  frozen  surface  of  the  soil,  the  relatively 
small  amount  remaining  being  conceivably  retained  by  the 
highly  absorbent  sphagnum  covering.  The  summer  rains, 
which,  although  frequent,  bring  comparatively  little  water, 
are  apparently  no  more  than  sufficient  to  supply  the  trans- 
piration loss  of  the  plants  exposed  to  almost  continuous  winds 
and  often  to  bright  sunshine  for  many  hours  a  day. 

Eoots   penetrate  this   dry  layer   only   to   a   slight   extent, 


190  Melanose  and  Stem-End  Rot  [388 

although  organic  deposits  occur  down  to  the  frost  line. 
These  deposits  are  lamelliform,  and  each  appears  to  be  con- 
tinuous from  its  lowest  point  to  the  surface  of  the  soil. 
Whether  they  originated  from  the  decay  of  roots  that  had 
penetrated  this  layer  while  it  contained  more  water  than  it 
does  now.,  or  whether  they  were  formed  by  slow  seepage 
from  the  surface,  cannot  be  decided  from  the  information  at 
hand.  The  occurrence  of  small  landslides  in  which  dry  soil 
was  found  above  and  below  the  layer  in  which  the  slipping 
occurred,  indicates.,  however,  that  water  may  move  in  a  thin 
sheet  of  soil  and  either  form  these  deposits  by  carrying  or- 
ganic matter  from  the  surface,  or,  finding  them  ready  formed, 
traverse  them  to  the  deeper  portions.  Since  these  layers  are 
rich  in  organic  matter  it  is  probable  that  their  constituents 
would  cohere  when  frozen,  which  is  not  true  of  the  dryer 
soil  about  them.  This  may  perhaps  account  for  the  state- 
ments often  made  that  in  the  winter  or  spring,  frozen  soil 
may  be  encountered  at  the  surface  and  also  below  it,  in 
sheets,  at  intervals. 

Whether  due  to  this  drying  and  being  frozen  in  the  dry 
condition,  or  to  other  more  obscure  causes,  the  soil  of  this 
dry  layer  is  often  flocculated  to  such  a  degree  that  it  resem- 
bles a  mass  of  small  clay  pellets.  Even  after  wetting  this 
flocculated  soil  retains  its  spherulate  character. 


THE    GEOGRAPHICAL    DISTRIBUTION    OF    THE    CITRUS 
DISEASES,    MELANOSE    AND    STEM-END    ROT 

By  H.  S.  FAWCETT 

A  general  survey  of  the  citrus  districts  of  the  United 
States  and  Cuba  has  shown  that  the  distribution-areas  of 
some  of  the  important  fungus  diseases  are  not  coextensive 
with  the  areas  where  the  host  is  cultivated.  This  fact  is 
strikingly  brought  out  by  an  examination  of  the  distribu- 
tion of  some  of  the  diseases  that  have  been  present  in  these 
regions  for  a  long  time. 


389]  H.  8.  Fawcett  191 

An  interesting  example  of  an  old,  well-known  disease  with 
a  rather  limited  distribution  is  melanose,  which  is  due  to 
Phomopsis  citri.  The  fungus  produces  small,  brown  pus- 
tules on  the  surface  of  rapidly  growing  leaves,  twigs  and 
fruit.  It  was  discovered  in  1892  and  was  first  definitely 
described,  by  Webber,  in  1897.  At  that  time  melanose  was 
already  a  rather  serious  disease  in  the  middle  portion  of  the 
peninsula  of  Florida.  During  the  past  20  years,  citrus 
nursery  stock  has  been  freely  interchanged  between  different 
parts  of  Florida,  and  thousands  of  acres  in  Cuba  have  been 
brought  into  citrus  culture  for  the  first  time,  the  stock  for 
planting  being  derived  from  Florida,  and  yet  the  area  over 
which  the  disease  is  now  of  serious  commercial  importance 
is  confined  roughly  between  the  parallels  of  27%°  and 
291/2°  N.  latitude  in  Florida. 

Southward  from  this  area  melanose  gradually  becomes 
less  and  less  severe  and  it  finally  disappears  entirely,  so  that 
the  southernmost  citrus  districts  of  the  state  are  free  from 
it.  In  Cuba,  if  the  disease  occurs  at  all,  it  is  of  no  commer- 
cial importance;  I  was  unable  to  find  any  evidence  of  it  in 
the  island  in  January,  1914.  North  of  the  Florida  area  of 
most  serious  injury,  melanose  occurs  in  a  less  severe  form, 
and  a  mild  form  of  the  same  disease  has  been  reported  for 
southern  Alabama  and  Louisiana,  but  it  is  apparently  not 
serious  in  these  regions.  No  trace  of  this  disease  has  ever 
been  found  in  California. 

The  same  Phomopsis  that  produces  melanose  also  plays  a 
part  in  the  so-called  stem-end  rot  of  mature  or  nearly  mature 
citrus  fruits,  and  it  is  an  interesting  fact  that  this  fruit  rot 
has  never  been  known  to  be  serious  outside  of  the  areas 
where  melanose  is  also  of  commercial  importance.  Like 
melanose,  stem-end  rot  has  not  been  reported  as  occurring 
either  in  Cuba  or  in  California. 

The  reasons  for  the  peculiar  distribution  of  Phomopsis 
citri,  as  above  described,  are  not  at  all  understood,  and  we 
cannot  regard  our  knowledge  of  melanose  and  stem-end  rot 
as  at  all  nearly  complete  until  a  properly  substantiated  ex- 


192  Melanose  and  Stem-End  Eot  [390 

planation  of  these  geographical  limitations  may  be  found. 
Such  problems  as  this  are  worthy  of  serious  attention.  Some 
of  the  logical  possibilities  of  this  particular  case  may  be 
mentioned,  by  way  of  preparing  for  further  observations  and 
for  constructive  experimentation. 

One  possibility  that  always  presents  itself  in  connection 
with  a  limited  geographical  distribution  of  any  parasite  is 
that  sufficient  opportunity  or  time  may  not  yet  have  been 
afforded  for  the  parasite  to  become  distributed  throughout 
the  area  occupied  by  the  host.  But  this  possibility  seems  not 
to  apply  in  the  present  case.  As  has  been  mentioned,  after 
melanose  had  become  common  in  central  peninsular  Florida 
there  took  place  a  free  interchange  of  many  kinds  of  citrus 
nursery  stock  between  Florida,  on  the  one  hand,  and  Cali- 
fornia and  Cuba,  on  the  other.  Many  carloads  of  young 
citrus  trees  were  shipped  from  nurseries  located  in  the 
Florida  area  where  this  Phomopsis  was  most  virulent,  no 
effective  quarantine  regulations  were  in  operation  at  that 
time,  and  it  is  impossible  that  the  fungus  has  not  long  since 
been  thoroughly  distributed.  All  or  nearly  all  of  the  citrus 
varieties  grown  in  Florida  have  been  planted,  at  one  time 
or  another,  in  California,  and  the  recent  and  extensive 
Cuban  plantings  have  been  made  with  nursery  stock  from 
Florida. 

Of  course,  climatic  conditions  may  furnish  an  explanation 
of  the  facts  here  dealt  with,  but  the  climatic  relations  of  a 
fungus  like  Phomopsis  citri  are  probably  even  more  complex 
than  are  those  of  higher  plants.  For  the  growth  of  such  a 
parasite  it  is  not  only  necessary  that  the  climatic  conditions  be 
suitable  for  this  organism,  but  it  is  also  essential  that  the  com- 
plex of  these  conditions  be  naturally  so  arranged  or  balanced 
that  the  host-plant  may  be  in  just  the  proper  state  to  favor 
the  virulent  development  of  the  parasite.  The  time  factor 
is  especially  important  in  the  process  of  infection;  it  must 
happen  that  the  host  is  in  a  condition  to  be  readily  infected 
just  at  the  time  when  the  fungus  spores  reach  it. 


391]  H.  8.  Fawcett  193 

One  of  the  necessary  conditions  -for  the  occurrence  of 
melanose,  when  Phomopsis  is  present,  appears  to  be  a  con- 
siderable degree  of  air  humidity,  at  the  season  of  most  rapid 
growth  of  new  shoots  and  of  the  fruit,  and  the  absence  of 
the  disease  in  California  may  possibly  be  accounted  for  by 
the  dryness  of  the  air  at  the  time  when  the  trees  are  most 
susceptible  to  infection.  This,  however,  does  not  seem  to 
be  a  sufficient  reason  for  the  absence  of  melanose  in  the 
southernmost  parts  of  Florida  and  Cuba. 

Edgerton  has  recently  emphasized  the  apparent  bearing 
of  temperature  conditions  on  the  occurrence  of  certain  plant 
diseases  in  sub-tropical  climates.  He  is  convinced  that  the 
absence  of  anthracnose  in  beans  grown  at  certain  seasons  in 
Louisiana  is  due  to  the  fact  that  the  average  temperatures 
for  those  seasons  are  above  the  optimum  for  the  growth  of 
the  pathogenic  fungus.  If  this  is  true  in  the  case  of  anthrac- 
nose it  may  also  be  true  in  the  case  of  melanose.  The  first 
requirement  for  a  test  of  this  suggestion  is,  of  course,  some 
definite  knowledge  concerning  the  temperature  relations  of 
Phomopsis  itself,  and  experimentation  is  now  in  progress 
in  this  direction. 


PRELIMINARY  NOTE  ON   THE  RELATION  OF   TEMPE- 
RATURE TO  THE  GROWTH  OF  CERTAIN 
PARASITIC  FUNGI  IN  CULTURES 

By  H.  S.  FAWCETT 


Interest  in  the  temperature  relations  of  plant  growth  is 
rapidly  increasing,  and,  as  improved  methods  become  avail- 
able, increasingly  precise  studies  are  being  made  of  the  in- 
fluence of  temperature  upon  growth  as  variously  measured. 
The  study  upon  which  the  writer  is  at  present  engaged  aims 
to  compare  the  temperature-growth  curves  for  cultures  of 
a  number  of  fungi  that  produce  diseases  of  citrus  trees  and 
that  are  confined  to  limited  geographical  areas.  It  is  hoped 

13 


194  Temperature  and  Growth  of  Fungi  [392 

that  the  results  obtained  may  be  of  value,  not  only  in  inter- 
preting the  geographical  distribution  and  seasonal  occurrence 
of  these  diseases,  but  in  suggesting  further  means  for  their 
control. 

A  suitable  solid  medium  in  petri  dishes  is  employed,  a 
transfer  (of  spores  or  a  small  piece  of  mycelium)  being 
made  to  the  center  of  each  culture  dish,  and  the  resulting 
growth  is  measured  in  terms  of  the  24-hourly  increase  in 
the  mean  diameter  or  radius  of  the  nearly  circular  area 
occupied  by  the  fungus.  Various  precautions  are  taken  to 
have  all  conditions,  excepting  that  of  temperature,  as  nearly 
alike  as  possible  throughout  the  entire  investigation. 

The  preliminary  work  so  far  carried  out  has  been  con- 
fined largely  to  Pythiacystis  citrophthora,  which  attacks  both 
the  trunk  and  fruit  of  the  lemon  tree.  To  illustrate  the 
kind  of  results  obtained,  at  the  temperatures  10°,  20°,  28° 
and  33 °C.  the  radial,  24-hourly  growth-rates  of  this  fungus 
were  2.5,  6,  7.5  and  2.6mm.,  respectively.  For  a  rise  of 
temperature  from  10°  to  20°  the  growth  rate  was  thus 
somewhat  more  than  doubled,  from  20°  to  28°  it  increased 
25  per  cent.,  and  at  33°  the  rate  was  nearly  the  same  as 
at  10°.  This  kind  of  a  relation  between  the  growth-rate  and 
temperature  was  of  course  to  be  expected,  and  interest  in 
this  research  will  lie  largely  in  the  differences  between  the 
temperature-growth  curves  of  the  different  fungi,  especially 
in  the  differences  between  their  optimum  temperatures  for 
growth. 

Although  bacteria  and  fungi,  as  studied  by  other  work- 
ers, appear  to  exhibit  gradually  diminished  growth-rates 
when  temperature  and  the  other  environmental  conditions 
are  maintained  unchanged  for  a  long  time,  yet  no  such  slow- 
ing down  of  growth  has  been  encountered  with  this  Pythia- 
cystis; for  example,  the  same  growth-rate  has  been  observed 
to  continue  unchanged  for  a  period  of  eight  days  or  more. 


393]  E.  E.  Free  195 


SYMPTOMS   OF   POISONING   BY   CERTAIN   ELEMENTS, 
IN  PELARGONIUM  AND   OTHER  PLANTS 

By  E.  E.  FKEE 


In  connection  with  other  experiments  on  the  effects  of  pois- 
onous elements  on  plants,  qualitative  tests  have  been  made 
of  the  symptoms  of  poisoning  exhibited  by  the  common  cul- 
tivated geranium  (Pelargonium  zonale)  and  by  several  other 
plants,  under  the  action  of  certain  poisonous  elements.  The 
plants  were  grown  in  soil  under  ordinary  greenhouse  condi- 
tions. The  poisons  were  applied  by  pouring  the  proper  solu- 
tions on  the  soil  when  the  latter  was  sufficiently  dry  to 
absorb  and  retain  all  of  the  added  solution.  Seven  elements 
were  applied  to  Pelargonium  in  five  concentrations  each. 
These  were  the  following.  Concentrations  are  in  parts  of  the 
poisonous  element  per  million  parts  of  soil  by  weight. 

Concentrations 
p.  p.  m. 

Arsenic,  as  trioxide    (As203) 2  to  500 

Boron,  as  borax    (Na^BA) 2  to  500 

Copper,   as  sulphate    (CuS04) 4  to  1000 

Iron,  as  ferrous  sulphate    ( FeS04 ) 20  to  5000 

Lead,  as  nitrate    (Pb(N03)2) 4  to  1000 

Manganese,  as  sulphate    (MnSOJ 8  to  .2000 

Zinc,  as  sulphate    (ZnS04) 8  to  2000 

In  addition  to  these  seven  elements  the  following  were  ap- 
plied in  one  concentration  only,  namely  500  parts  per  mil- 
lion:— barium,  as  chloride  (BaCl2) ;  bromine,  as  potassium 
bromide  (KBr)  ;  cobalt,  as  sulphate  (CoSOJ  ;  chromium,  as 
potassium  chromate  (K2Cr04)  ;  iodine,  as  potassium  iodide 
(KI)  ;  lithium,  as  sulphate  (Li2S04)  ;  mercury,  as  mercuric 
chloride  (HgCl2)  ;  nickel,  as  sulphate  (MS04)  ;  silver,  as 
nitrate  (AgN03)  ;  uranium,  as  uranyl  nitrate  (U02(N03)2)  ; 
and  vanadium',  as  chloride  (VC12).  All  of  these  elements 
except  iron  were  applied  to  Impatiens  sultani,  Coleus  blumei 


196  Symptoms  of  Poisoning  in  Plants  [394 

and  View  faba  as  well  as  to  Pelargonium.  The  first  ten 
elements  (arsenic,  boron,  copper,  manganese,  zinc,  lead,  mer- 
cury, iodine,  chromium,  and  barium)  were  applied  also  to 
Chrysanthemum  frutecens,  Bryophyllum  calycinum  and 
castor  bean  (Ricinis  communis) .  Except  as  noted,  all  appli- 
cations were  in  the  concentration  of  500  parts  of  the  poison- 
ous element  per  million  parts  of  soil.  In  order  to  avoid  local 
injuries  to  the  stem  large  applications  were  frequently  divided 
and  added  in  several  portions  at  intervals  of  a  few  days. 

The  following  elements  gave  no  determinable  poisonous 
effects  on  any  plant,  in  the  concentrations  used:  arsenic, 
barium,  bromine,  cobalt,  copper,  lead,  manganese,  nickel, 
silver,  uranium,  vanadium  and  zinc.  A  slight  improvement 
of  color  and  general  condition  was  noticed  in  Pelargonium 
with  manganese  and  zinc.  There  was  also  a  slight,  but  un- 
mistakable, stimulation  of  the  growth  of  this  plant  by  arsenic 
in  the  higher  concentrations  but  this  conceivably  may  have 
been  due  to  some  chemical  action  in  making  more  available 
the  phosphorus  or  other  nutrients  in  the  soil. 

Pronounced  toxic  effects  were  observed  with  boron,  chro- 
mium, iodine,  lithium  and  mercury,  and  it  is  interesting 
that  these  effects  were  largely  so  specific  as  to  permit  imme- 
diate recognition  of  the  particular  poison  by  mere  inspection 
of  the  plant.  Thus  on  Pelargonium  the  effect  of  boron  is  the 
development  of  dark-green  areas,  1  to  5  mm.  wide,  inward 
from  the  edges  of  the  leaves.  This  altered  strip  gradually 
dries  and  hardens,  without  becoming  brown,  and  the  leaf 
falls  after  from  one  to  four  weeks.  The  dark-green  coloration 
does  not  extend  to  the  whole  leaf.  Lithium  shows  a  some- 
what similar  behavior,  but  the  altered  area  on  the  edge  of  the 
leaf  is  wider  and  is  a  light  gray-green  instead  of  dark  green. 
It  shows  a  very  characteristic  banding  of  the  color  in  narrow 
light  and  dark  lines  parallel  to  the  leaf  edge.  With  iodine 
the  leaves  turn  yellow  on  the  edges  and  this  yellowing  gradu- 
ally extends  inward  over  the  whole  leaf.  Not  until  the  leaf 
has  turned  entirely  yellow  does  it  fall  or  wilt  appreciably. 
Mercury  produces  a  somewhat  similar  yellowing  of  the  leaves, 


395]  E.  E.  Free  197 

but  wilting  begins  immediately  and  the  leaf  usually  falls 
long  before  it  is  entirely  yellow.  The  first  effect  of  chromium 
is  a  brown  discoloration  in  the  vascular  bundles  of  the  petioles 
and  veins.  This  is  followed  by  a  change  of  the  leaf  color 
to  a  dark  green,  and  the  early  fall  of  the  leaves.  The  regu- 
larity and  specificity  of  these  changes  is  attested  by  many 
repeated  observations  on  different  leaves  and  different  plant 
individuals.  Similar  specificities  were  observed  with  the 
plants  other  than  Pelargonium.  It  seems  probable,  therefore, 
that  the  recognition  of  a  poisonous  agent  by  the  specific  symp- 
toms of  its  action  is  as  possible  with  these  plants  as  with 
animal  organisms. 

Certain  features  of  the  localization  of  injury  in  the  plants 
is  suggestive  of  relations  to  transpiration.  For  instance,  with 
boron  and  lithium  on  Pelargonium  the  limitation  of  injury  to 
the  edges  of  the  leaves  implies  its  occurrence  only  where  the 
final  evaporation  of  the  water  of  the  transpiration  stream 
localizes  the  poison  in  a  concentration  sufficient  to  be  toxic.  A 
similar  conclusion  follows  from  the  fact  that  injury  occurs 
first,  and  sometimes  only,  on  leaves  of  moderate  age,  that  is 
on  those  which  are  in  their  period  of  most  vigorous  transpira- 
tion. Younger  leaves  and  older  leaves  on  the  same  plant  are 
usually  uninjured.  Similarly,  when  a  Pelargonium  plant 
is  poisoned  but  not  killed,  by  either  boron,  lithium,  mercury 
or  iodine,  new  leaves  produced  thereafter  do  not  show  injury 
while  they  are  young,  but  develop  it  after  from  two  to  six 
weeks  of  growth.  The  same  observation  was  made  with 
boron  and  iodine  on  Chrysanthemum.  Further  confirmation 
is  the  failure  of  Bryophyllum,  which  has  a  very  low  transpir- 
ing power,  to  show  injury  with  any  poison  except  boron. 
Even  in  this  case  the  injury  developed  eleven  weeks  later  than 
it  did  on  Pelargonium  and  all  the  other  plants.  All  of  this 
evidence  suggests  that,  in  the  concentrations  used,  the  poisons 
were  carried  into  the  plant  incidentally  by  the  transpiration 
stream  and  produced  injury  only  when  and  where  the  evap- 
oration of  the  transpired  water  increased  the  concentration  of 
the  poison  in  a  local  tissue  area.  The  symptoms  observed 


198  Aeration  [396 

with  chromium  imply  that  it  may  form  an  exception  to  this 
behavior,  but  even  with  this  element  it  was  observed  that 
Pelargonium  leaves  were  injured  only  when  of  middle  age; 
young  and  old  leaves  being  unaffected. 


THE  EFFECT  OF  AERATION  ON  THE  GROWTH   OF 
BUCKWHEAT  IN  WATER-CULTURES 

By  E.  E.  FREE 


In  connection  with  other  work  on  the  oxygen  requirements 
of  plant  roots  experiments  have  been  made  on  the  relations 
between  the  degree  of  aeration  of  the  culture  solution  and 
the  growth  of  buckwheat  in  water-cultures.  The  plants  were 
grown  in  quart  jars  in  the  usual  manner,  three  plants  to  a 
jar.  The  solution  was  that  found  by  Shive  1  to  be  the  best 
for  the  growth  of  buckwheat.  The  experiment  included  18 
jars  divided  into  six  sets  of  three  jars  each.  One  set,  used 
as  control,  was  handled  according  to  the  usual  technique,  with 
free  access  of  air  to  the  solution.  Another  set  was  sealed, 
the  seal  about  the  young  plants  being  made  with  a  parafme- 
vaseline  mixture  according  to  the  method  of  Briggs  and 
Shantz.2  With  the  third  set,  a  slow  stream  of  air  was  bubbled 
through  the  culture  solution,  a  bubble  about  5  mm.  in  diam- 
eter passing  about  once  a  second.  The  three  remaining  sets 
were  treated  in  the  same  way  with  oxygen,  nitrogen  and 
carbon  dioxide,  respectively.  Precautions  were  taken  to  re- 
move deleterious  impurities  from  the  gases.  Water  evaporated 
from  the  culture  solutions  was  replaced  when  necessary. 

The  cultures  with  oxygen,  nitrogen  and  air  showed  no  de- 
parture from  the  open  controls  or  from  the  sealed  cultures. 


1  Shive,   John   W.,    "  A   three-salt    nutrient    solution    for    plants." 
Amer.  Jour.  Bot.  2:  157-160,  1915. 

2  Briggs,  L.  J.,  and  Shantz,  H.  L.,  "A  wax  seal  method  for  deter- 
mining the  lower  limit  of  available  soil  moisture."       Bot.  Gass.  51: 
210-219.     1911. 


39T]  E.  E.  Free  and  S.  F.  Trelease  199 

Eate  of  growth  and  weight  of  dry  matter  produced  was  essen- 
tially the  same  in  all.  All  plants  grew  to  maturity  and 
nearly  all  set  seed.  It  appears  that  the  degree  of  aeration  of 
the  culture  solution  is  without  important  influence  on  the 
growth  of  buckwheat  under  the  conditions  described;  a  con- 
clusion that  may  have  value  in  general  water-culture  prac- 
tice. ' 

It  may  be  added  that  in  the  cultures  treated  with  carbon 
dioxide  the  plants  sickened  and  wilted  within  a  few  hours 
and  died  within  a  few  days.  In  one  case  the  stream  of  car- 
bon dioxide  was  replaced  after  the  first  day  by  a  stream  of 
air.  In  this  case  the  plants  recovered  partially  but  remained 
permanently  smaller  than  the  other  plants  of  the  experi- 
ment. !  * 


THE  EFFECTS  OF  CERTAIN  MINERAL  POISONS   ON 

YOUNG   WHEAT   PLANTS   IN   THREE-SALT 

NUTRIENT  SOLUTIONS 

By  E.  E.  FREE  and  S.  F.  TRELEASE 


A  large  part  of  the  experimentation  which  has  been  done 
in  the  past  on  the  effects  of  mineral  poisons  on  plants  is  un- 
satisfactory and  contradictory,  for  the  reason  that  the  nutri- 
ent materials  available  to  the  plants,  in  the  soil  or  nutrient 
solution  employed,  were  different  in  the  different  experi- 
ments. The  reactions  of  plants  to  the  various  poisons  appear 
to  vary  with  such  differences  in  the  available  nutrients.  In 
connection  with  other  work  on  nutrient  solutions,,  tests  have 
been  made  on  the  effects  of  certain  poisonous  elements  on 
the  growth  of  young  wheat  plants  in  water-cultures.  The 
salt  combination  used  in  the  nutrient  solution  was  that  found 
by  Shive  *  to  be  best  for  the  production  of  dry  weight  of 

1  Shive,  J.  W.,  "A  three-salt  nutrient  solution  for  plants."  Amer. 
Jour.  Bot.  2:  157-160.  1915.  Idem,  "A  study  of  physiological  bal- 
ance in  nutrient  media."  Physiol.  Res.  I:  327-397.  1915.  (Especi- 
ally p.  352-364.) 


200  Mineral  Poisons  [398 

tops  for  wheat.  The  total  concentration  of  the  solution  corre- 
sponded to  an  osmotic  pressure  of  1.75  atmospheres  at  25°  C. 
The  technique  was  essentially  the  same  as  that  employed  by 
Shive. 

The  minimum  concentrations  at  which  the  various  poisons 
began  to  produce  clearly  marked  injury,  as  indicated  by 
smaller  dry  weights  of  tops,  are  given  in  the  following  table. 
Concentrations  are  "given  in  parts  of  the  poisonous  element 
per  million  parts  of  the  nutrient  solution.  In  most  cases  the 
concentration  at  which  injury  begins  is  not  sharply  marked, 
and,  therefore,  the  figures  given  have  only  approximate  quan- 
titative value. 

Toxic 

Concentration 

Element  Compound  used  of  element. 

p.  p.  m. 

Arsenic   trioxide    ( As203) 1 

Boron    borax     (Na,B40T) 10 

Cobalt  sulphate    (CoSOJ 7 

Copper    sulphate    ( CuSO4 ) 1 

Manganese   sulphate    (MnS04) 1000 

Mercury    bichloride     (HgCl2) 40 

Nickel sulphate   (NiS04) 5 

Vanadium chloride    ( VC12) 20 

Zinc    sulphate  (ZnS04) 100 

Experiments  were  made  also  with  lead,  as  lead  nitrate 
(Pb(ISr03)2),  and  with  uranium  as  uranyl  nitrate 
(U02(N~03)2),  but  both  of  these  elements  were  precipitated 
by  the  constituents  of  the  nutrient  solution.  The  maximum 
concentrations  obtainable  in  the  solution  were  approximately 
100  parts  per  million  in  case  of  lead  and  20  parts  per  million 
in  the  case  of  uranium.  Neither  of  these  was  toxic. 

A  slight  stimulating  effect,  indicated  by  greater  produc- 
tion of  tops,  was  observed  with  manganese,  between  the  con- 
centrations of  4  and  20  parts  per  million,  and  with  vanadium, 
between  2  and  7  parts  per  million.  There  was  a  clear  stimu- 
lation in  the  uranium  cultures  above  a  concentration  of  50 
parts  per  million  of  uranium,  but  it  is  possible  that  this  was 


399]  E.  E.  Free  and  S.  F.  Trelease  201 

due  to  the  nitrate  in  the  uranium  salt.  No  stimulation  was 
observed  with  any  other  of  the  elements  tested. 

This  failure  to  secure  determinable  stimulating  effects  with 
most  of  the  elements  is  surprising  and  is  contrary  to  the  re- 
sults of  many  previous  investigations.  It  seems  possible  that 
it  may  be  due  to  the  fact  that  the  Shive  solution,  in  the  con- 
centration and  salt  proportions  employed,  is  itself  slightly 
toxic  because  of  its  high  content  of  magnesium.  This  solu- 
tion, although  it  gives  the  best  production  of  dry  wefght  of 
tops,  produces  plants  many  of  which  show  the  morphological 
modifications  characteristic  of  magnesium  poisoning.2  These 
observations  form  one  of  several  bits  of  evidence  which  sug- 
gest that  the  best  growth  of  a  plant,  as  measured  by  produc- 
tion of  dry  matter,  occurs  only  when  the  plant  is  slightly 
poisoned.  It  may  be  a  general  rule  that  increased  growth 
is  the  first  response  to  agents  or  circumstances  which  would 
prove  injuriously  toxic  in  greater  concentration  or  on  longer 
exposure. 

"We  have  found  some  confirmation  of  this  suggestion  in  our 
experiments  on  the  effect  of  boron  on  Canada  field  pea.  Using 
the  Shive  solutions  containing  salt  proportions  other  than 
the  ones  above  referred  to,  and  adding  borax  to  these  solu- 
tions, considerable  stimulations  were  obtained.  The  experi- 
ments need  to  be  extended  and  confirmed,  but  the  present 
indication  is  that  borax  is  stimulating  in  those  nutrient  solu- 
tions which  contain  less  magnesium  than  the  one  giving  great- 
est dry  weight  of  tops.  In  other  words,  slight  poisoning, 
such  as  that  caused  by  magnesium  or  boron,  is  essential  for 
the  production  of  the  greatest  dry  weight  of  tops.  Either 
magnesium  or  boron  will  serve.  Probably  other  poisons 
would  be  equally  efficacious. 


2  Shive,  loo.  tit..  (2),  p.  370-374.  Tottingham,  William  E.,  "A 
quantitative  chemical  and  physiological  study  of  nutrient  solutions 
for  plant  cultures."  Physiol.  Res.  1 :  133-245.  1914. 


202  Leaf-Product  [400 


LEAF-PRODUCT  AS  AN   INDEX   OF   GROWTH   IN 
SOY-BEAN 

By  F.  MERRILL  HILDEBRANDT 


It  has  been  pointed  out  by  McLean  x  that  the  sum  of  the 
products  of  the  length  and  breadth  of  all  the  leaflets  on  a 
soy-bean  plant  4  weeks  old  is  approximately  proportional  to 
the  total  leaf  area  of  that  plant,,  and  he  adds  that  the  leaf 
area  is  itself  nearly  proportional  to  the  total  dry  weight  of 
stem  and  leaves.  The  sum  just  mentioned  has  been  called 
the  leaf-product  by  the  same  writer,  his  observations  being 
based  on  measurements  obtained  at  two  stations  in  Maryland, 
Easton  and  Oakland,  in  the  project  carried  out  during  the 
summer  of  1914  by  the  Maryland  State  Weather  Service  in 
co-operation  with  the  Laboratory  of  Plant  Physiology  of  the 
Johns  Hopkins  University.  That  project  included  similar 
studies  of  the  relation  of  plant  growth  to  climatic  conditions 
at  seven  other  stations  in  Maryland,  besides  Easton  and  Oak- 
land, and  the  present  paper  aims  to  bring  out  the  fact  that 
this  interesting  relation  between  leaf-product,  leaf  area  and 
dry  yield  of  tops  applies  generally  to  the  soy-bean  data  for 
all  nine  stations. 

If  the  method  proposed  by  Livingston  2  and  McLean,  of 
employing  the  growth  rates  of  standard  plants  as  indices  for 
the  comparison  of  different  climates  as  these  influence  plant 
growth  in  general,  is  to  be  of  value,  it  is  of  course  necessary 
that  suitable  plant  characteristics  be  chosen  for  measurement 
in  determining  the  growth  rates,  and  it  is  desirable  that  the 
measurements  be  such  as  may  be  made  from  time  to  time 
without  injury  to  the  plants.  The  most  generally  accepted 


1  McLean,  F.   T.,  "A  preliminary  study  of  climatic  conditions  in 
Maryland,  as  related  to  plant  growth."       Physiol.  Res.  2:   129-208. 
1917. 

2  Livingston,  B.  E.,  and  McLean,   F.  T.,  "A  living  climatological 
instrument."     Science,  n.  s.  43:  362-363.     1916. 


401]  F.  M.  Hildebmndt  203 

criterion  of  plant  growth,  dry  weight  of  tops,  can  be  obtained 
but  once  for  any  individual  plant,  since  the  plant  is  destroyed 
during  the  determination.  Also,  the  accurate  determination 
of  leaf  area  is  very  difficult  unless  the  plants  are  destroyed. 
On  the  other  hand,  as  McLean  has  emphasized,  leaf  dimen- 
sions may  be  obtained  repeatedly  during  the  development 
of  the  plant  without  serious  danger  of  inflicting  injury.  It 
may  therefore  be  of  considerable  importance  if  leaf  area,  and 
even  dry  weight,  can  be  satisfactorily  estimated  for  soy-bean 
by  the  employment  of  the  leaf-product  as  an  index. 

The  general  procedure  followed  in  obtaining  the  observa- 
tional data  upon  which  are  based  the  results  here  considered 
has  been  described  by  McLean,  who  conducted  all  the  cultures 
personally  (see  his  paper  cited  above).  For  the  present  pur- 
pose it  is  sufficient  to  state  that  cultures,  each  of  6  soy-bean 
plants,  were  started  from  the  seed  every  two  weeks  through- 
out the  summer  season,  at  each  of  the  nine  stations  employed, 
and  that  plant  measurements  were  taken  after  about  two  and 
after  about  four  weeks  of  growth.  Dry  weight  and  actual 
leaf  area  were  determined  only  for  the  four-week  periods,  the 
plants  being  then  destroyed,  but  the  lengths  and  breadths 
of  all  leaflets  were  obtained  for  both  the  two-week  and  the 
four-week  periods.  Consequently,  to  study  the  correlation 
between  total  leaf  area  and  total  leaf -product  per  plant,  only 
the  four-week  data  are  available,  and  these  are  the  ones  here 
considered.  Thus,  each  of  the  nine  stations  is  represented 
by  a  series  of  consecutive  four-week  culture  periods,  each 
period  overlapping  on  to  the  next  preceding  and  next  follow- 
ing one.  A  large  number  of  different  sets  of  climatic  con- 
ditions is  thus  represented  by  the  whole  series  for  the  nine 
stations,  which  includes  97  4- week  culture  periods  in  all. 

The  leaf  measurements  here  dealt  with  have  all  been  ob- 
tained by  the  writer  from  photographic  contact  prints  made 
by  Dr.  McLean  from  the  fresh  leaves  immediately  after  these 
were  removed  from  the  plants.  Areas  were  obtained  from  the 
same  prints  with  a  planimeter.  The  leaflet  length  was  taken 
from  tip  to  junction  of  blade  and  petiole  for  each  leaflet,  and 


204  Leaf-Product  [402 

the  corresponding  leaflet  breadth  was  measured  at  the  point 
of  greatest  width,  at  right  angles  to  the  long  axis  of  the 
leaflet.  Since  soy-bean  leaflets  are  approximately  elliptical 
in  form  and  since  the  area  of  an  ellipse  is  proportional  to 
the  product  of  its  axes,  the  leaflet-product  (length  times 
breadth)  of  any  leaflet  should  be  nearly  proportional  to  the 
area  of  that  leaflet.  Whether  this  relation  may  hold  during 
the  growth  of  the  leaflet  under  different  sets  of  climatic  con- 
ditions depends  upon  how  nearly  the  elliptical  form  is  re- 
tained. The  sum  of  the  individual  leaflet-products  of  any 
plant,  which  is  the  total  leaf -product  for  that  plant,  should 
be  approximately  proportional  to  the  total  leaf  area  of  the 
plant,  if  the  relation  given  above  holds.  In  the  discussion 
that  follows  it  will  be  shown  that  such  an  approximate  propor- 
tionality does  exist  in  the  case  of  the  four-week  soy-bean 
plants. 

In  order  to  find  out  whether  the  actual  area  of  the  leaves 
in  these  cultures  was  proportional  to  the  leaf-products,  the 
ratio  of  the  two  quantities  was  worked  out  for  a  number  of 
the  stations.  It  was  found  that  the  leaf -product  divided  by 
the  leaf  area  gives  a  number  that  varies  only  slightly  from  the 
value  1.28.  In  other  words,  if  we  measure  the  two  diameters 
of  the  leaflets  of  a  four-week  soy-bean  plant,  multiply  these 
two  numbers,  and  add  the  products,  a  number  is  obtained 
which,  when  divided  by  1.28,  closely  approximates  the  actual 
leaf  area  of  that  plant.  Instead  of  using  the  sum  of  the 
products  of  length  and  breadth  as  an  index  of  the  area  per 
plant  we  may  use  the  sum  of  the  squares  of  the  lengths  of 
the  leaflets  or  the  sum  of  the  squares  of  the  breadths  of  the 
leaflets  of  the  plant.  The  numbers  thus  secured  do  not,  how- 
ever, bear  as  nearly  constant  a  ratio  to  the  actual  leaf  area 
as  does  the  total  leaf-product,  and  hence  neither  is  as  satis- 
factory an  index  of  the  area  as  is  the  leaf -product  itself. 

One  of  the  most  interesting  properties  of  the  four-week 
soy-bean  plant  is  that  the  dry  weight  of  stem  and  leaves  is 
proportional,  approximately,  to  the  total  leaf  area.  Having, 
therefore,  a  means  by  which  the  leaf  area  may  be  conveniently 


403]  F.  M.  Hildebrandt  205 

measured,  it  is  possible  to  calculate  the  dry  weight  of  the 
plant  approximately,  by  multiplying  the  leaf-area  by  the 
proper  constant.  The  proportionality  between  the  weight  of 
the  plant  and  its  leaf  area  is  not  quite  so  constant  as  that 
between  leaf  area  and  leaf  product,  but  in  the  great  majority 
of  cases  the  variation  in  the  ratio  of  dry  weight  to  leaf  area, 
from  a  constant  value,  is  less  than  10  per  cent.  The  rela- 
tions given  hold  over  a  very  wide  range  of  climatic  conditions 
and  for  plants  varying  in  height  from  2  or  3  centimeters 
to  18  or  20  centimeters.  Since  none  of  the  plants  in  these 
experiments  were  grown  to  maturity,  it  is  impossible  to  say 
whether  this  relation  holds  up  to  that  time. 

From  the  foregoing  facts  it  may  be  concluded  that  the  dry 
weight  and  leaf  area  of  soy-beans  4  weeks  old  from  the  seed 
can  be  determined  approximately  from  their  leaflet  dimen- 
sions. Soy-bean  should  therefore  be  very  suitable  for  use  as  a 
standard  plant  for  the  measurement  of  climate  in  the  man- 
ner suggested  by  Livingston  and  McLean,  since  the  rate  of 
its  growth  can  be  approximately  determined  from  easily  ob- 
tained leaf  measurements.  Also,  the  properties  of  soy-bean 
given  above  should  make  it  a  useful  plant  for  any  piece  of 
physiological  research  in  which  it  is  desired  to  know  approxi- 
mately the  dry  weight  of  the  plant  used,  at  various  stages 
of  its  development. 


A  METHOD  FOR  APPROXIMATING  SUNSHINE  INTENSITY 
FROM    OCULAR    OBSERVATIONS    OF    CLOUDINESS 

By  F.  MERRILL  HILDEBRANDT 


Air  temperature,  the  evaporating  power  of  the  air,  and 
sunshine  intensity  may  be  considered  the  main  climatic  con- 
ditions affecting  plant  growth  and  one  of  the  first  essentials 
in  ecological,  agricultural,  and  forestal  studies  is  some  means 
by  which  these  may  be  measured  in  the  field.  We  are  al- 
ready provided  with  instruments  for  measuring  the  first  two, 


206  Sunshine  Intensity  [404 

but  the  means  thus  far  available  for  measuring  sunshine  in- 
tensity are  difficult  to  apply  in  field  studies.  A  method  is 
here  presented  by  which  a  roughly  approximate  index  of  sun- 
shine intensity  during  any  period  for  any  station  may  be 
made  from  records  such  as  are  kept  by  the  observers  of  the 
II.  S.  Weather  Bureau. 

The  total  heat  equivalent  of  the  actual  sunshine  for  any 
given  period  at  a  station  is  primarily  a  function  of  three 
terms:  (1)  the  maximum  possible  number  of  hours  of  sun- 
shine (determined  by  latitude  and  season)  ;  (2)  the  mean 
intensity  of  full  sunshine  for  the  period  and  station,  ex- 
pressed in  terms  of  heat;  (3)  the  condition  of  the  sky> 
whether  overcast,  partly  overcast  or  clear.  The  daily  values 
for  the  first  two  of  these  terms  vary  in  a  regular  manner 
throughout  the  year  at  any  given  place,  and  the  ones  for  the 
third  term  are  roughly  stated  in  the  observer's  records,  as  just 
mentioned.  It  was  desired  to  combine  these  three  terms  so 
as  to  get  approximations  of  sunshine  intensity  for  a  number 
of  different  stations  in  Maryland  for  the  summer  of  1914, 
in  order  to  make  comparisons  of  the  summer  march  of  sun- 
shine intensity  with  that  of  corresponding  measurements  of 
plant  growth.  This  has  been  accomplished  in  the  manner 
described  below. 

The  first  two  terms  are  combined  in  the  ordinates  of  the 
graph  given  by  Kimball1  for  the  maximum  possible  total 
radiation  received  per  day  at  Mount  Weather,  Virginia. 
Since  this  station  is  at  about  the  same  latitude  as  the  stations 
in  Maryland,  the  ordinate  values  may  be  taken  as  approximate 
measures  of  the  total  radiation  intensity  for  the  corresponding 
dates  at  any  place  in  the  state.  These  values  represent  the 
total  amount  of  heat,  expressed  in  gram-calories  per  square 
centimeter  of  horizontal  surface  exposed,  received  from  the 
sun  and  sky  on  clear  days  at  Mount  Weather.  The  method 


1  Kimball,  Herbert  H.,  "  The  total  radiation  received  on  a  hori- 
zontal surface  from  the  sun  and  sky  at  Mount  Weather.  Monthly 
Weather  Rev.  42:  474-487.  1914.  (See  especially  fig.  8,  p.  484). 


405]  F.  M.  HiUebrandt  207 

of  using  the  graph  and  a  weather  observer's  report  for  estimat- 
ing sunshine  will  be  best  shown  by  an  example. 

Suppose  it  is  desired  to  estimate  the  average  daily  sunshine 
intensity  for  some  station  in  the  general  region  of  Mount 
Weather,  for  the  first  week  of  August.  The  average  ordinate 
value  for  this  week  is  first  obtained  from  KimbalPs  graph. 
For  periods  as  short  as  a  week  or  two  this  may  be  done  by 
averaging  the  values  for  the  first  and  last  days  of  the  period, 
since  the  curve  may  be  taken  as  a  straight  line  for  such  short 
intervals.  From  the  report  of  the  weather  observer  at  the 
place  in  question,  the  number  of  clear,  partly  cloudy,  and 
cloudy  days  is  next  determined  for  the  days  August  1  to 
August  7,  inclusive,  and  some  arbitrary  weighting  is  given 
to  each  kind  of  day.  We  may,  for  instance,  call  clear  days 
whole  days  of  sunshine,  partly  cloudy  days  half  days  of  sun- 
shine, and  assume  that  cloudy  days  are  days  without  any  sun- 
shine. The  scheme  of  weighting  adopted  must,  of  course,  be 
adhered  to  in  all  the  estimates  made  for  different  periods  and 
stations.  The  system  of  weighting  given  above  was  used  in  the 
studies  for  which  this  method  of  approximating  sunshine  was 
developed.  By  summing  these  weighted  daily  values  a  num- 
ber is  obtained  which  represents  the  equivalent  number  of 
clear  days  for  the  period  considered.  Suppose,  in  the  example 
selected,  that  this  equivalent  number  of  clear  days  is  3.5, 
which  is  0.5  of  the  total  number  of  days  in  the  period.  The 
latter  value  may  be  termed  "  the  coefficient  of  clear  weather." 
By  multiplying  the  average  daily  intensity  value  for  clear 
days,  as  obtained  from  the  curve,  by  this  coefficient  of  clear 
weather  a  number  is  secured  that  is  a  rough  approximation 
of  the  average  daily  sunshine  intensity  for  the  week. 

While  it  is  certain  that  solar  radiation  affects  plants  in 
other  ways  than  through  its  heating  effect,  it  is  no  less  cer- 
tain that  by  far  the  greater  part  of  the  energy  of  sunshine 
absorbed  by  plants  is  converted  into  heat  (largely  as  latent 
heat  of  the  vaporization  of  water),  and  it  seems  probable  that 
the  other  effects  produced  upon  the  plant  may  be  more  or  less 
proportional  to  the  total  energy  equivalent  of  sunshine.  The 


208  Moisture  Equilibrium  [406 

method  of  measurement  of  light  here  given,  although  it  is  only 
a  rough  approximation  and  depends  on  the  heating  effect  of 
the  sunshine,  has  been  shown,  as  a  matter  of  fact,  to  give 
numbers  rather  definitely  correlated  with  plant  growth.  It 
has  been  found,  for  instance,  that  the  amount  of  dry  sub- 
stance produced  per  unit  of  leaf  area  in  young  soy-bean 
plants  decreases  from  the  beginning  to  the  end  of  the  growing 
season,  in  a  manner  which  generally  parallels  a  corresponding 
fall  in  the  light  intensity  values  as  determined  in  the  manner 
described  above. 


MOISTURE  EQUILIBRIUM  IN  POTS   OF  SOIL  EQUIPPED 
WITH  AUTO-IRRIGATORS 

By  F.  S.  HOLMES 


While  the  auto-irrigator  devised  by  Livingston  1  has  been 
employed  by  several  writers,2  for  maintaining  uniform  mois- 
ture conditions  in  potted  soils,  the  details  of  adjustment  re- 
quired by  this  device,  for  different  soils  and  for  maintaining 
different  moisture  contents,  remain  still  to  be  worked  out. 
In  order  to  throw  some  light  upon  this  general  question,  a 
study  of  three  different  soils  was  undertaken  to  determine 
the  relation  between  the  equilibrium  point  of  the  soil-moisture 
content  and  the  number  of  irrigator  cups  employed. 

One  soil  was  a  medium-fine  white  sand,  one  was  a  light 


1  Livingston,   B.   E.,    "  A  method  of  controlling  plant  moisture." 
Plant  World  II:  39-40.     1908. 

2  Hawkins,  Lon  A.,  "  The  porous  clay  cup  for  the  automatic  water- 
ing of  plants."     Plant  World  13:  220-227.     1910.     Transeau,  E.  N., 
"  Apparatus  for  the  study  of  comparative  transpiration."     Bot.  Gaz. 
52:   54-60.     1911.     Livingston,   B.   E.,   and  Lon  A.   Hawkins,   "The 
water  relation  between  plant  and  soil."     Carnegie  Inst.  Wash.  Pub. 
204:  5-48.     1915.     Hibbard,  R.  P.,  and  0.  E.  Harrington,  "Depres- 
sion of  the  freezing-point  in  triturated  plant  tissues,  and  the  mag- 
nitude of  this  depression  as  related  to  soil  moisture."     Physiol.  Res. 
I:   441-454.     1916. 


407]  F.  S.  Holmes  209 

clay  loam,  and  the  third  was  a  mixture,  of  equal  parts,  by 
volume,  of  the  other  two.  Pots  of  each  kind  of  soil  were 
equipped  with  auto-irrigators  having  respectively  one,  three 
and  five  porous  cups,  thus  giving  nine  combinations.  The 
containers  were  tinned  sheet-metal  cylinders  approximately 
15  cm.  in  diameter  and  17  cm.  in  height.  The  porous  cups 
were  evenly  distributed  within  the  soil  mass,  when  but  one 
was  used  it  occupied  the  center.  A  mercury  tube  was  so  ar- 
ranged that  all  water  entered  the  soil  against  a  pressure  of 
from  5  to  6  cm.  of  a  mercury  column.  Evaporation  was  pre- 
vented by  sealing  covers  on  the  containers  with  plastiline. 
The  cylinders  were  filled  to  a  uniform  depth  of  16  cm.,  an  at- 
tempt being  made  to  secure  as  uniform  packing  as  possible 
throughout  the  entire  series. 

Weighings  of  the  containers  were  made  at  intervals  of  two 
or  three  days,  for  the  first  twenty  days,  and  thereafter  at 
weekly  intervals,  to  determine  the  rates  at  which  water  was 
being  absorbed  and  to  approximate  the  moisture  content  of 
the  soil.  Approximately  three-fourths  of  the  water  taken 
up  by  the  loam  and  by  the  sand-loam  mixture  occurred  dur- 
ing the  first  ten  days,  but  the  sand  took  up  only  about  one- 
half  of  its  total  amount  in  the  same  period.  Approximate 
equilibrium  of  the  soil  moisture  content  was  reached  in  about 
seventy-five  days,  in  the  case  of  the  loam;  in  about  eighty 
days  in  the  case  of  the  mixture ;  and  in  about  ninety  days  in 
the  case  of  the  sand.  The  number  of  porous  clay  cups  em- 
ployed seemed  to  have  no  influence  upon  the  length  of  time 
required  for  the  attainment  of  equilibrium  by  either  the  loam 
or  the  loam-sand  mixture.  With  the  sand,  however,  the 
number  of  cups  appeared  to  influence  the  length  of  this  time 
period.  With  three  cups  equilibrium  was  reached  sooner  than 
with  one,  and  with  five  sooner  than  with  three. 

When  the  weighings  of  the  cylinders  and  observations  on 
the  water  reservoirs  showed  that  the  soil  had  ceased  to  absorb 
water,  the  cylinders  were  opened  and  samples  were  taken  for 
soil-moisture  determinations.  Two  1-cm.,  full-depth  cores 
were  taken  from  each  container,  one  core  from  as  near  a  cup 

14 


210  Moisture  Equilibrium  [408 

as  possible,  the  other  as  far  removed  as  possible.  The  aver- 
age of  the  two  was  taken  to  be  representative  of  the  entire 
soil  mass.  Each  sample  was  removed  and  dried  in  eight 
2-cm.  sections,  so  that  it  was  possible  to  study  both  the  ver- 
tical and  horizontal  distribution  of  the  soil  moisture  in  the 
cylinder.  There  was  a  horizontal  as  well  as  a  vertical  varia- 
tion of  small  magnitude  in  the  soil-moisture  content  of 
all  the  cylinders,  the  water  content  being  almost  always 
somewhat  higher  near  the  cups  and  at  the  bottom  of  the  soil 
mass.  The  distribution  of  the  moisture,  both  horizontal 
and  vertical,  was  more  uniform  in  the  sand-loam  mixture 
than  in  the  sand,  and  also  more  uniform  in  the  loam  than 
in  the  mixture.  The  number  of  porous  cups  used  had  very 
little  influence,  if  any,  upon  the  soil  moisture  content  of  the 
loam;  it  varied  as  100  : 106  : 103,  for  the  containers  having 
one,  three  and  five  porous  cups,  respectively.  This  influence 
of  the  number  of  cups  was  more  pronounced  in  the  case  of 
the  sand-loam  mixture,  the  variation,  with  one,  three  and 
five  cups,  being  100  : 147  : 168.  With  the  sand  there  was  a 
still  more  marked  effect,  the  moisture  contents  for  the  three 
cup  numbers  being  100  : 191  :  277  in  this  case.  These  vari- 
ations are  all  smaller  than  the  corresponding  variation?  in 
the  value  of  the  ratio  of  cup  number  to  soil  mass,  these  values 
varying  as  100  :  321  :  576,  for  all  three  soils.  For  the  con- 
tainers with  three  cups  the  actual  average  soil  moisture  con- 
tent (on  the  basis  of  dry  weight)  was  11.0  per  cent,  for  the 
loam,  5.2  per  cent,  for  the  mixture,  and  1.1  per  cent,  for  the 
sand. 

With  the  pressure  here  used  (averaging  5.5  cm.  of  a  mer- 
cury column)  the  soil  moisture  content  at  equilibrium  was 
too  low  for  plant  cultures  in  the  sand  and  perhaps  also  in  the 
sand-loam  mixture.  In  the  loam,  however,  it  was  surely  high 
enough  to  supply  plants  with  the  water  necessary  for  their 
growth  under  ordinary  greenhouse  conditions. 


409]  E.  8.  Johnston  211 


SEASONAL  VARIATIONS  IN  THE  GROWTH-RATES   OF 

BUCKWHEAT  PLANTS  UNDER  GREENHOUSE 

CONDITIONS 

By  EAEL  S.  JOHNSTON 


Seasonal  variations  in  greenhouse  plants  are  of  considerable 
importance  to  plant  growers  as  well  as  to  experimenters  in 
plant  physiology,,  but  it  is  especially  with  reference  to  physi- 
ological experimentation  that  this  study  was  undertaken. 
When  it  is  necessary  to  repeat  an  experiment  on  plant  growth 
it  often  occurs  that  the  results  of  the  second  experiment  are 
in  more  or  less  pronounced  disagreement  with  those  of  the 
first.  Since  the  controlled  external  conditions  must  be  re- 
garded as  the  same-  for  both  experiments,  such  disagreement 
appears  to  be  related  either  to  initial  differences  in  the  plants 
used  (internal  conditions)  or  to  uncontrolled  external  con- 
ditions as  these  vary  with  the  season.  The  first  of  these  pos- 
sibilities is  probably  not  as  important  as  the  second  in  most 
cases,  for  care  is  usually  taken  to  select  plants  for  the  second 
experiment  that  are  apparently  similar  to  those  used  for  the 
first.  While  this  problem  of  similarity  of  internal  conditions 
of  different  lots  of  plants  is  a  very  difficult  one  and  is  hardly 
susceptible  of  quantitative  study  at  the  present  time,  it  is 
quite  possible  to  carry  out  studies  on  the  relation  of  growth 
to  the  usually  uncontrolled  (or  only  partially  controlled) 
external  conditions  of  a  greenhouse.,  as  these  conditions 
change  throughout  the  year.  A  portion  of  the  results  ob- 
tained from  such  study  are  here  presented. 

A  set  of  similar  water  cultures  was  started  every  two  weeks 
and  each  was  continued  for  a  period  of  four  weeks,  so  that 
the  periods  of  successive  sets  overlapped.  A  single  set  con- 
sisted of  ten  plants,  each  suitably  supported  in  a  glass  jar  con- 
taining about  425  cc.  of  nutrient  solution.  These  jars  were 
covered,  to  exclude  most  of  the  light  from  the  plant  roots. 
The  solution  was  renewed  at  the  middle  of  each  four-week 


212  Variations  in  Growth-Rates  [410 

period.  At  the  end  of  each  week  several  different  kinds  of 
measurements  of  the  plants  were  made,  and  the  data  thus 
obtained  were  studied  to  bring  out  the  seasonal  variations  in 
growth-rates.  Since  the  solutions  were  alike  for  all  sets  and 
the  seedlings  used  were  selected  for  likeness,  it  is  fair  to  sup- 
pose that  observed  differences  in  growth-rates,  between  the 
different  sets  of  cultures,  must  have  been  mainly  due  to  fluc- 
tuations in  the  uncontrolled  conditions  of  the  surroundings, 
such  as  temperature,  light  and  the  evaporating  power  of  the 
air. 

The  experiments  were  carried  out  in  one  of  the  experiment 
greenhouses  of  the  Laboratory  of  Plant  Physiology.  Xo 
artificial  shade  was  applied  to  the  greenhouse.  Two  sets  of 
cultures  were  always  carried  out  simultaneously,  one  under 
unmodified  greenhouse  conditions  and  the  other  in  a  cheese- 
cloth chamber  in  the  greenhouse,  but  the  data  obtained  from 
the  chamber  cultures  will  not  be  dealt  with  in  the  present 
paper.  A  continuously  rotating  table  76  cm.  in  diameter  was 
used  in  each  case,  the  jars  standing  near  the  margin  of  the 
table. 

Japanese  buckwheat,  Fagopyrum  esculentum  Moench.,  was 
employed,  and  Shive's *  three-salt  nutrient  solution,  no. 
R  4C2  (total  osmotic  value  1.75  atmospheres),  was  used 
throughout  the  entire  series.  Aside  from  renewing  the 
solution  at  the  middle  of  the  four-week  period,  water  was 
always  added  at  the  end  of  the  third  week  of  growth,  to  bring 
the  solution  back  to  its  original  volume.  When  the  transpi- 
ration rates  were  excessive  a  still  further  addition  of  water 
was  made  during  the  fourth  week  of  growth,  in  order  to  pre- 
vent the  root  systems  from  becoming  unduly  exposed.  The 
first  experiment  began  Feb.  14,  1916. 

Of  the  plant  characteristics  measured  at  the  end  of  each 
four-week  period  of  growth,  only  stem  height,  total  dry  weight 
and  total  area  of  the  leaves  (one  surface  only)  are  here  con- 


1Shive,  John  W.,  "A  study  of  physiological  balance  in  nutrient 
media."     Physiol.  Res.    I:  327-397.     1915. 


411] 


E.  8.  Johnston 


213 


sidered,  the  values  obtained  being  expressed  as  averages  per 
plant,  for  each  of  the  four-week  periods.  The  temperature 
conditions,  the  evaporating  power  of  the  air  and  the  intensi- 
ty of  radiation  were  recorded  for  each  of  the  two  exposures, 
but  these  are  left  out  of  the  present  consideration. 

The  results  obtained  from  these  three  plant  measurements 
are  shown  in  the  accompanying  table,  wherein  all  the  values 
are  expressed  in  terms  of  the  corresponding  value  for  the 
period  ending  May  22.  In  this  table  the  dates  of  beginning 
and  ending  of  the  several  culture  periods  are  shown  in  the  first 
two  columns.  Each  value  given  in  the  table  represents  an 
average  growth-rate  representing  a  single  plant,  for  a  time 
period  of  28  days. 

EXPERIMENTAL  DATA 


Period 

Stem 

Total 

Total 

Av'ge  of 

Beginning 

Ending 

Height. 

Dry  Wt. 

Leaf  Area 

Wt.  &  Area 

Feb.  14 

Mar.  13 

.73 

.50 

.63 

.57 

Feb.  28 

Mar.  27 

.83 

.62 

.81 

.72 

Mar.  13 

Apr.  10 

.85 

.72 

.77 

.75 

Mar.  27 

Apr.  24 

.94 

.80 

.76 

.78 

Apr.  10 

May     8 

.98 

.89 

.76 

.83 

Apr.  24 

May  22 

1.00 

1.00 

1.00 

1.00 

(67.5  cm.) 

(1.338  g.) 

(213.5  sq, 

,  cm.) 

May    8 

June     5 

.93 

.91 

.93 

.92 

May  22 

June  19 

.83 

.93 

.98 

.96 

June     5 

July     3 

.73 

.93 

1.00 

.97 

(214.1  sq. 

cm.) 

June  19 

July  17 

.77 

.88 

.88 

.88 

July     3 

July  31 

.97 

.91 

.92 

.92 

July  17 

Aug.  14 

1.04 

.82 

.83 

.83 

July  31 

Aug.  28 

.91 

.67 

.77 

.72 

Auff    14 

Sept.  11* 

•*••*•  *-*g»      -LTE 

Aug.  28 

Sept.  25 

1.07 

.76 

.70 

.73 

Sept.  11 

Oct.    9 

.97 

.55 

.58 

.57 

Sept.  25 

Oct.  23 

.78 

.34 

.43 

.39 

Oct.     9 

Nov.     6 

.79 

.36 

.51 

.44 

The  different  kinds  of  growth-rates  are  seen  to  vary  inde- 
pendently, from  period   to  period,  but  two   of  the  growth 


Data  not  obtained  because  of  insect  injury  to  plants. 


214  Variations  in  Growth-Rates  [412 

criteria,,  weight  and  area,  show  variations  that  correspond 
rather  closely.  Both  of  these  show  high  rates  for  the  sum- 
mer and  low  ones  for  the  spring  and  autumn.  Judged  by 
dry  weight  of  plant  produced  the  growth-rate  reached  its 
maximum  (1.34  g.  per  plant,  in  28  days)  with  the  period 
ending  May  22,  but  this  value  remains  high  until  after  the 
period  ending  July  31.  Judged  by  the  total  leaf  area,  the 
rate  does  not  attain  its  maximum  (214  sq.  cm,  per  plant,  in 
28  days)  until  later,  this  occurring  with  the  period  ending 
July  3,  but  this  value  is  high  for  the  three  preceding  periods 
and  for  the  two  following.  Roughly  speaking,  it  may  be  said 
that  these  two  criteria  give  rates  that  are  proportional,  and 
that  they  agree  in  indicating  a  period  of  very  rapid  growth, 
extending  from  about  May  8  to  about  July  17.  Before  the 
period  with  its  middle  at  May  8  the  rates  are  lower,  forming 
a  generally  ascending  series,  from  the  very  low  values  of  the 
early  spring,  and  after  the  period  with  its  middle  at  July  17 
they  decrease  rapidly  (with  a  low  secondary  maximum  indi- 
cated for  the  period  ending  Sept.  25)  to  very  low  values  in 
the  autumn. 

The  rates  of  growth  in  height  fail  to  show  this  sort  of 
seasonal  march;  the  maximum  rate  (49  cm.  per  plant,  in  28 
days)  being  shown  for  the  period  ending  July  3,  but  this 
rate  also  has  very  low  values  for  the  periods  ending  March 

13,  Oct.  23  and  JSTov.  6.     By  this  criterion,  the  maximum  for 
the  period  considered  (72.5  cm.  per  plant,  in  28  days)  occurs 
with  the  period  ending  Sept.  25,  but  pronounced  secondary 
maxima  are  shown  for  the  periods  ending  May  22  and  Aug. 

14.  This  rate  of  growth  in  height  appears  to  vary  consider- 
ably from  period  to  period,  but  in  a  manner  entirely  inde- 
pendent of  the  general  advance  of  the  season  and  quite  inde- 
pendent of  the  variations  in  rates  of  increase  in  dry  weight 
and  in  leaf  area.     As  far  as  these  data  go,  it  therefore  ap- 
pears that  there  is  nothing  in  the  usually  uncontrolled  ex- 
ternal conditions  of  a  greenhouse  in  this  climate,  that  may 
be  expected  to  produce  a  regular  march  of  growth-rates  in 


413]  E.  8.  Johnston  215 

height,  for  healthy  buckwheat  plants,  during  the  spring,  sum- 
mer and  autumn. 

McLean  2  has  pointed  out  the  approximate  proportionality 
of  the  rates  of  production  of  dry  weight  and  leaf  surface, 
for  the  first  four  weeks  of  growth  of  soy-bean  plants,  and  he 
also  found  that  the  rate  of  stem  elongation  varied  quite  differ- 
ently from  the  rates  of  production  of  dry  weight  and  surface. 
It  may  be  of-  fundamental  significance  that  two  plants  as 
widely  different,  in  many  other  respects,  as  are  buckwheat  and 
soy-bean,  exhibit  these  remarkable  agreements  in  the  manner 
of  variation  in  these  three  growth-rates  with  differences  in 
the  climatic  conditions  of  the  environment. 

The  general  agreement  between  the  seasonal  variations 
shown  by  the  rates  of  increase  in  dry  weight  and  in  leaf  area 
is  so  marked  that  it  appears  quite  permissible  to  combine  these 
two  criteria  by  averaging  their  relative  values,  to  give  a  single 
value  representing  both  together,  and  the  averages  so  derived 
are  given  in  the  last  column  of  the  table.  Of  course,  these 
two  measurements  of  growth-rate  are  not  directly  commensu- 
rable, and  the  average  values  here  introduced  are  to  be  re- 
garded merely  as  numerical  indices  of  the  rates  of  growth. 
This  value  has  its  maximum  (1.00)  for  the  period  ending 
May  22,  and  it  of  course  shows  high  value  for  the  five  fol- 
lowing periods.  Its  minimum  value  (0.39)  occurs  for  the 
period  ending  Oct.  23. 

Of  course  there  are  many  other  considerations  to  receive 
attention  in  a  study  of  this  sort,  but  it  already  seems  clear 
that  a  regular  and  pronounced  seasonal  variation  in  the  rates 
of  production  of  dry  weight  and  leaf  area  may  be  expected  in 
healthy  buckwheat  plants  growing  in  a  greenhouse  in  this 
kind  of  climate,  although  the  same  nutrient  medium  is  al- 
ways employed.  If  the  weight-area  indices  be  represented 


2  McLean,  Forman  T.,  "A  preliminary  study  of  climatic  conditions 
in  Maryland,  as  related  to  plant  growth."  Physiol.  Res.  2:  129-208. 
1917. 


216  Variations  in  Growth-Rates  [414 

graphically  they  give  only  comparatively  slight  variations 
from  a  smooth  curve  and  the  actual  graph  may  readily  be 
smoothed  to  give  such  a  curve.  After  this  has  been  done  the 
ordinates  of  the  smoothed  curve,  corresponding  to  the  various 
culture  periods,  may  be  measured,  and  the  series  of  graphi- 
cally derived  values  thus  obtained  may  be  taken  as  a  tentative 
scale  to  indicate  approximately  the  relative  growth-rates  to  be 
expected  for  this  plant  in  these  general  surroundings.  Of 
course,  the  seasonal  march  of  the  climatic  conditions  in  this 
particular  greenhouse  must  be  expected  to  vary  from  year  to 
year,  and  it  surely  varies  from  greenhouse  to  greenhouse; 
nevertheless,  the  tentative  scale  derived  as  just  described  may 
be  of  value  in  several  ways. 

For  the  first  sixteen  four-week  periods  of  the  present 
study,  beginning  with  Feb.  14,  as  given  in  the  table  pre- 
sented above,  these  relative  seasonal  indices  of  growth-rate 
(by  either  dry  weight  or  leaf  area,  which  appear  to  be  propor: 
tional,  or  by  their  average)  are  respectively  as  follows :  61,  71, 
79,  86,  91,  96,  99,  100,  99,  96,  92,  87,  81,  75,  68,  61.  In  this 
scale  of  growth-rate  values  the  maximum  (100)  occurs  for 
the  period  ending  June  19,  and  it  represents  actual  average 
growth-rates,  as  obtained  in  this  study,  of  1.24  g.  of  dry 
weight  and  209  sq.  cm.  of  leaf  area  (one  surface  only),  per 
plant,  per  period  of  28  days.  While  these  derived  results 
are  extremely  tentative  and  probably  only  very  roughly  ap- 
proximate, it  is  clear  that  we  have  here  a  new  kind  of  descrip- 
tion of  the  climatic  conditions  of  this  greenhouse  for  the 
spring,  summer  and  autumn  of  1916,  these  conditions  and 
their  seasonal  march  being  described  in  terms  of  their  ability 
to  produce  dry  material  and  leaf  surface  in  the  standard  plant 
here  employed. 

By  such  a  method  as  this  the  climatic  plant-producing 
power  for  any  four-week  period  may  be  directly  compared 
with  that  of  any  other  similar  period,  no  matter  when  or 
where  these  periods  occur,  the  standard  plant  being  used  as  an 
automatically  integrating  instrument  for  the  measurement  of 


415]  W.  E.  Tottingham  217 

the  effective  climatic  conditions.  This  general  method  for 
the  comparative  study  of  climatic  conditions  has  been  sug- 
gested by  Livingston  and  McLean  3  and  a  first  attempt  at  its 
employment  was  carried  out  by  McLean  in  the  paper  already 
mentioned. 


ON  THE  RELATION  OF  CHLORINE  TO  PLANT  GROWTH 

By  W.  E.  TOTTINGHAM 

As  a  result  of  experiments  conducted  early  in  the  develop- 
ment of  the  water-culture  method,  chlorine  has  been  con- 
sidered as  one  of  the  unessential  elements  for  the  growth  of 
plants  in  general.  Nevertheless,  all  seeds  contain  more  or 
less  of  this  element  and  in  no  instance  has  a  plant  been  limit- 
ed to  this  original  source  of  chlorine  through  successive  gen- 
erations, so  that  it  may  still  be  said  that  the  question  here 
raised  has  never  been  really  tested.  Practically  all  soils  con- 
tain considerable  amounts  of  chlorine  in  the  form  of  chlorides 
and  its  occurrence  in  plants  appears  to  be  confined  to  this 
form.  That  this  element  may  have  important  effects  under 
some  conditions,  when  applied  as  an  agricultural  fertilizer, 
is  indicated  by  a  common  practice  in  some  parts  of  Europe, 
of  adding  common  salt  to  stimulate  the  growth  of  mangel- 
wurzel  and  of  mixed  meadow  grasses,  but  the  manner  in  which 
this  effect  is  produced  has  not  been  made  clear.  It  has  been 
observed  that  unrestricted  application  of  chlorides  may  lead 
to  poisoning  of  the  soil,  and  agriculturists  have  been  advised 
specially  against  the  use  of  potassium  chloride  as  a  source  of 
potassium  for  tobacco,  the  potato  and  the  sugar  beet.  Euro- 
pean investigators  have  reported  a  decreased  content  of  starch 
in  the  potato  tuber  as  a  result  of  the  substitution  of  this  salt 
for  potassium  sulphate. 


3  Livingston,  B.   E.,  and   McLean,   F.   T.,   "A  living  climatological 
instrument."     Science,  n.  s.  43:  362-363.     1916. 


218  Chlorine  and  Plant  Growth  [416 

The  investigations  here  considered  in  a  preliminary  way 
were  planned  to  supplement  our  knowledge  of  this  subject. 
They  are  as  yet  in  early  stages  of  progress,  having  been  begun 
under  the  auspices  of  the  Wisconsin  Agricultural  Experiment 
Station.  It  was  purposed  to  measure  the  responses  of  various 
plants,  in  form  and  in  the  weight  of  plant  material  produced, 
to  the  application  of  certain  chlorides,  and  to  determine  any 
specific  results  brought  about  by  this  application  of  chlorine, 
upon  the  chemical  composition  of  the  plants.  Greenhouse 
cultures  were  grown  in  nutrient  solutions,  in  pure  sand  and 
in  Miami  silt  loam,  and  field  cultures  were  grown  in  loam.  It 
may  be  said  of  these  greehouse  cultures,  which  were  partly 
carried  out  in  the  winter,  that,  while  growth  is  retarded  by  the 
decreased  light  intensities  of  the  winter  months,  the  partial 
control  of  climatic  and  soil  conditions  in  such  greenhouse  cul- 
tures assures  more  reliable  comparative  results  than  are  usually 
derived  from  field  plots,  with  their  natural  fluctuation  of 
climatic  conditions  from  season  to  season  and  of  fertility  from 
plot  to  plot. 

In  the  water-culture  experiments,  in  the  greenhouse,  the 
plants  were  grown  to  maturity,  in  either  Tottingham's  or 
Knop's  nutrient  solution,1  containing  Ca(ISr03)2,  KN03, 
MgS04  and  KH2P04,  in  proper  proportions,  with  a  trace  of 
iron  as  FeP04.  The  former  had  a  total  osmotic  concentration 
value  of  about  1.75  atmospheres  (0.4  per  cent,  of  salts  by 
weight)  and  the  total  osmotic  value  of  the  latter  was  about 
0.9  atmospheres  (0.2  per  cent,  of  salts  by  weight).  In  some 
cases  chlorine  was  introduced  by  replacing  the  MgS04  of  the 
4-salt  solution  with  a  molecularly  equivalent  quantity  of 
MgCl2,  in  other  cases  KN03  was  replaced  by  KC1,  and  in 
still  other  cases  NaCl  was  superimposed  upon  the  salts  usual- 
ly present.  Replacement  of  MgS04  by  MgCl2  resulted  in  an 
increased  length  of  roots,  for  pea,  wheat  and  clover,  amount- 


Nottingham,  W.  E.,  "A  quantitative  chemical  and  physiological 
study  of  nutrient  solutions  for  plant  cultures."  Physiol.  Res.  I : 
247-288.  1914. 


417]  W.  E.  Tottingham  219 

ing  to  from  100  to  300  per  cent.  This  gain  in  root  length 
was  correlated  with  somewhat  smaller  gains  in  dry  weight. 
With  wheat  and  clover  the  production  of  dry  weight  of  tops 
was  depressed  by  this  treatment  but  the  percentage  of  nitro- 
gen contained  in  the  dry  tops  was  unaffected.  It  will  be 
noted  that  the  interpretation  of  these  effects  is  complicated 
by  the  fact  that  sulphur  was  absent  where  chlorine  was  pres- 
ent in  the  solution. 

Buckwheat  was  grown  in  Knop's  solution  modified  by  hav- 
ing KN03  partly  or  wholly  replaced  by  KC1,  thus  avoiding 
the  omission  of  sulphur.  Such  treatment  led  to  a  slightly 
increased  production  of  stem  and  root  when  the  replacement 
was  only  partial,  but  complete  replacement  depressed  the  root 
length  and  the  dry  weight  of  roots  and  leaves,  the  amount  of 
water  lost  by  transpiration  being  proportionately  decreased. 
Total  replacement  of  KN03  by-Nad  depressed  growth  more 
than  when  KC1  was  used  and  transpirational  water  loss  was 
more  than  proportionately  decreased.  Comparison  with  the 
necessary  control  solutions  indicated  that  this  effect  is  to  be 
considered  specific  for  the  NaCl  molecule,  an  observation 
which  adds  to  the  accumulating  evidence  that  molecules  must 
be  taken  into  consideration,  and  not  ions  only,  in  dealing 
with  the  relations  between  the  plant  and  the  solutes  of  a 
nutrient  solution.  The  conclusion  of  earlier  investigators, 
that  chlorine  must  be  added  to  the  nutrient  solution  for  the 
complete  development  of  buckwheat,  finds  no  support  in  the 
present  work. 

The  sand  cultures  of  this  study  (also  in  the  greenhouse) 
were  conducted  on  20-kilogram  portions  of  sand,  in  open 
boxes  with  paraffined  inner  surfaces.  The  insoluble  salts 
were  incorporated  with  the  dry  sand  and  the  others  were 
added  in  successive  portions  of  solution.  The  total  applica- 
tion of  salts  was  about  0.25  per  cent,  of  the  dry  weight  of  the 
sand.  With  mangel-wurzel,  an  increase  of  from  40  to  120 
per  cent,  in  the  dry  weight  of  roots  resulted  from  the  applica- 
tion of  KC1  in  a  complete  fertilizer  ration,  but  greater  in- 


220  Chlorine  and  Plant  Growth  [418 

crease  followed  where  NaCl  was  superimposed  upon  the  usual 
complete  ration. 

For  the  greenhouse  cultures  in  Miami  silt  loam,  fifteen  or 
twenty  kilograms  of  air-dry  soil  were  employed,  in  cypress 
boxes,  the  salts  being  added  as  in  the  case  of  the  sand  cul- 
tures. The  total  application  of  salts  approximated  from  0.06 
to  0.15  per  cent,  of  the  dry  weight  of  the  soil. 

The  sugar  beet  produced  50  per  cent,  more  dry  substance 
(root)  when  chlorine  was  included  with  the  usual  salt  ration 
than  when  the  ration  without  chlorine  was  used.  The 
glucose  content  of  the  root  was  increased  somewhat,  percen- 
tagely  on  the  basis  of  dry  weight,  but  the  sucrose  content  was 
uninfluenced  by  this  treatment.  Preliminary  experiments 
with  the  radish  indicate  that  it  is  little  affected  by  the  chlorine 
supply,  while  the  growth  of  the  carrot  is  stimulated  and  that 
of  the  parsnip  is  depressed  as  regards  content  of  dry  matter 
and  percentage  of  sugars.  Similar  experiments  with  the  po- 
tato ("  Triumph  "  and  "  Eural  New  Yorker  "  varieties)  gave 
the  same  dry  weights  of  tubers,  whether  potassium  was  sup- 
plied as  the  chloride  or  as  the  sulphate. 

In  the  field  experiments,  sugar  beet  roots  showed  an  increase 
of  from  10  to  30  per  cent.,  by  weight,  where  NaCl  was  ap- 
plied to  the  soil  at  the  rate  of  from  260  to  520  pounds  per 
acre,  as  compared  with  those  of  the  unfertilized  plot.  The 
glucose  content  was  increased,  but  that  of  sucrose  was  unaf- 
fected by  this  treatment.' 

The  potato  ("  Triumph  "  variety)  produced  the  same  yield, 
both  of  total  and  marketable  tubers,  whether  supplied  with 
potassium  as  KC1  or  as  K2S04 ,  in  the  complete  fertilizer 
ration.  The  addition  of  NaCl  without  other  salts  depressed 
the  yield.  Another  experiment  with  potato  ("Eural  New 
Yorker"  variety)  showed  that  the  starch  content  and  cook- 
ing qualities  of  the  tuber  were  the  same  whether  potassium 
was  supplied  as  KC1  or  as  K2S04,  in  the  complete  fertilizer. 
Fertilization  with  NaCl  alone  gave  tubers  of  lower  starch 
content  and  poor  quality.  It  thus  appears  that  the  depress- 


419]  W.  E.  Tottingham  221 

ing  effect  of  chlorine,  as  reported2  for  starch  content  and 
cooking  quality  of  potato  tubers,  does  not  obtain  under  all 
conditions  of  culture,  and  fails  to  make  itself  manifest  with 
the  climatic  and  soil  conditions  of  these  experiments. 

The  results  outlined  above  leave  the  question  of  the  in- 
fluence of  the  chlorine  ion  and  chlorides  upon  plants  still  in 
a  very  complicated  and  unsatisfactory  condition.  Perhaps 
the  most  valuable  general  conclusion  that  can  be  drawn  from 
a  review  of  all  the  work  so  far  reported  upon  this  subject,  is 
that  the  influence  here  considered  appears  to  be  impossible 
of  any  general  statement.  It  appears  that  the  effect  of 
chlorine  upon  any  given  plant  depends  upon  the  nature  of 
the  plant,  upon  the  soil  conditions  (aside  from  chloride  con- 
tent) and  upon  the  conditions  of  the  surroundings  generally 
classed  as  climatic.  It  may  be  that  each  particular  case  of 
acceleration  or  retardation  of  growth  processes  by  chlorine 
presents  a  special  problem,  and  that  broad  generalizations 
are  not  to  be  expected  until  much  progress  has  been  made 
toward  the  interpretation  of  environmental  complexes  as  a 
whole ;  for  the  present,  we  are  constrained  to  study  these  con- 
ditions piecemeal.  It  seems  that  the  promise  of  progress  in 
these  very  complicated  problems  of  agricultural  science  lies 
largely  in  more  complete  experimental  control  of  the  very 
numerous  conditions  that  make  up  the  environment  of  the 
plant.  It  is  the  summed  or  integrated  effects  of  all  of  these 
that  is  registered  by  our  plants  in  growth  and  crop  produc- 
tion. 


2  For  example,  see:  Siichting,  H.,  "  Ueber  die  schadigende  Wirkung 
der  Kalirohsalze  auf  die  Kartoffel."  Lcmdw.  Versuchsst.  61:  397- 
449.  1905. 


222  Salt  Proportions  [420 


A  STUDY  OF  SALT   PROPORTIONS  IN  A  NUTRIENT 

SOLUTION  CONTAINING  CHLORIDE,  AS  RELATED 

TO  THE  GROWTH  OF  YOUNG  WHEAT  PLANTS 

By  S.  F.  TRELEASE 


Chlorine  has  been  considered  an  unnecessary  element  in  the 
nutrition  of  most  plants,,  but  it  seems  to  have  produced  a 
beneficial  influence  in  certain  cases  that  have  been  recorded. 
There  is  some  practical  as  well  as  scientific  interest  in  the 
question  thus  raised,  since  potassium  chloride  is  frequently 
used  as  an  agricultural  fertilizer,  and  the  influence  of  the 
chlorine  thus  put  into  the  soil  may  not  be  without  impor- 
tance. In  the  experiments  of  which  this  is  a  preliminary 
report  the  chlorine  ion  was  introduced  into  nutrient  solutions 
that  already  contained  all  the  essential  elements  usually  ab- 
sorbed by  plant  roots.  These  essential  elements  (N,  S,  P, 
Ca,  Mg,  K,  and  Fe)  may  be  supplied  to  the  young  wheat 
plants  as  a  nutrient  solution  containing  the  three  salts 
Ca(N03)2,  MgS04,  and  KH2P04,  with  a  trace  of  iron  as 
FeP04.  To '  introduce  chlorine,  KC1  was  added  to  the 
list  just  given,  thus  making  a  4-salt  solution.  A  solu- 
tion made  from  these  four  salts  was  used  by  Knop  and 
Nobbe,  and  Grafe *  recommends  these  same  salts  as  most  gen- 
erally useful.  Detmer2  employed  one  set  of  proportions  of 
these -four  salts,  and  this  solution  has  been  designated  by  Tot- 
tingham  3  as  Detmer^s  solution.  In  the  experiment s  consid- 
ered in  this  paper  the  same  general  methods  were  used  as  were 


1  Grafe,   V.     "  Ernahrungsphysiologisches   Praktikum   der   hoheren 
Pflanzen."     Berlin,   1914. 

2  Detmer,  W.,  "  Practical  plant  physiology."     Translated  by  S.  A. 
Moor.     London,   1898. 

3  Tottingham,  W.  E.,  "A  quantitative  chemical  and  physiological 
study   of  nutrient   solutions   for   plant   cultures."     Physiol    Res.    I : 
133-245.     1914. 


421]  8.  F.  Trelease  223 

employed  by  Tottingham  and  by  Shive.4  The  total  concen- 
tration of  the  nutrient  solution  corresponded  to  an  osmotic 
pressure  of  approximately  1.6  atmospheres  at  25°  C.,  and  the 
relative  proportions  of  the  four  component  salts  were  varied 
in  all  possible  ways,  by  increments  of  one-tenth  of  this  total 
concentration.  Eighty-four  different  solutions  were  thus  in- 
cluded in  each  complete  set;  all  of  these  had  approximately 
the  same  total  osmotic  concentration,  but  no  two  had  the 
same  relative  proportions  of  the  four  component  salts.  Six 
plants  were  grown  in  each  culture,  and  the  solutions  were 
renewed  every  four  days. 

The  various  salt  proportions  proved  to  be  very  different  in 
their  ability  to  produce  growth  of  the  young  wheat  plants. 
As  has  been  found  by  other  writers,  the  solution  giving  the 
greatest  dry  yield  of  tops  is  not  the  one  giving  the  greatest 
yield  of  roots,  and  the  solution  producing  the  highest  dry 
weight  of  tops  and  roots  together  has  still  another  set  of  salt 
proportions.  The  highest  dry  yield  of  tops  was  obtained 
with  the  following  partial  volume-molecular  concentrations 
of  the  four  main  constituent  salts:  0.0067M  KC1,  0.0138M 
KH2P04,  0.0047M  Ca(N03)2,  and  0.0081M  MgS04.  A 
trace  of  iron  was,  of  course,  added,  as  a  suspension  of  ferric 
phosphate. 

This  highest  yield  of  wheat  tops  with  the  4-salt  solution 
containing  chlorine  was  not  higher,  however,  than  was  ob- 
tained, in  these  experiments,  with  the  best  salt  proportions, 
without  chlorine,  of  the  Birner  and  Lucanus  (Shive)  3-salt 
solution  and  of  the  Knop  (Tottingham)  4-salt  solution.  If 
the  best  salt  proportions  are  used  in  all  three  cases  these  three 
very  different  types  of  solutions  give  practically  the  same 
result.  It  therefore  appears  to  be  impossible  to  improve  the 
growth  of  young  wheat  plants,  as  this  occurs  in  Shive's  and 
Tottingham's  best  salt  proportions,  by  the  introduction  of 


4  Shive,  J.  W.,  "A  three-salt  nutrient  solution  for  plants."  Amer. 
Jour.  Bot.  2:  157-160.  1915.  Idem,  "A  study  of  physiological  bal- 
ance in  nutrient  media."  Physiol.  Res.  I:  327-397.  1915. 


224  Salt  Proportions  [422 

chlorine  into  the  solution.  Furthermore,  the  best  4-salt  solu- 
tion with  chlorine  contains  the  three  essential  salts  in  nearly 
the  same  proportions  as  those  in  which  they  occur  in  Shive's 
best  3-salt  solution,  which  has  the  following  composition: 
0.0180M  KH2P04,  0.0052M  Ca(N03)2,  and  0.0150M  MgS04. 
The  main  difference  in  this  respect  lies  in  the  Mg/Ca  quoti- 
ent; in  Shive's  best  solution  this  quotient  has  the  value  2.88, 
and  in  the  best  4-salt  solution  with  chlorine  it  has  the  value 
1.72.  Both  are  characterized  by  relatively  high  proportions  of 
KH2P04,  and  low  proportions  of  Ca(N03)2,  which  is  rather 
surprising,  since  many  nutrient  solutions  heretofore  proposed 
have  a  relatively  high  concentration  of  Ca(N03)2.  In  gen- 
eral, the  occurrence  of  the  morphological  leaf  modifications 
tions  recognized  as  magnesium  injury  in  such  series  as  these 
(Tottingham,  Shive)  was  not  altered  by  the  presence  of  the 
chlorine  ion  in  the  solution. 

A  marked  improvement  over  Detmer's  salt  proportions  was 
obtained  in  the  present  study.  The  best  solution  gave  an  in- 
crease in  dry  weight  of  tops  of  27  per  cent,  and  20  per  cent., 
respectively,  over  the  yields  obtained  in  two  solutions  of  the 
present  series  closely  resembling  Detmer's  in  salt  proportions. 
An  even  more  marked  improvement  over  the  growth  obtained 
with  Detmer's  exact  proportions  is  reported  by  Shive,  for  his 
best  3-salt  solution,  which,  as  has  been  mentioned,  gave  prac- 
tically the  same  yield  as  did  the  best  4-salt  solution  used  in 
this  study. 

While  it  seems  impossible  to  obtain  higher  top  yields  of  these 
plants  in  the  4-salt  solution  containing  chlorine,  than  in  the 
3-salt  solution  without  this  element,  it  should  nevertheless  be 
remarked  that  the  presence  of  chlorine  may  diminish  to  some 
extent  the  retarding  effect  produced  by  the  three  salts  of  the 
essential  elements  when  these  are  not  in  the  best  proportions. 
Thus,  if  we  start  with  an  unbalanced.  3-salt  solution,  a  proper 
addition  of  chlorine  may  sometimes  accelerate  the  growth  of 
the  plants.  The  addition  of  a  non-essential  element  may  im- 
prove the  physiological  properties  of  a  solution  containing  the 
essential  elements  in  improper  proportions. 


423]  8.  F.  T release  225 

Perhaps  the  main  result  of  this  study  is,  in  general,  that 
no  matter  whether  we  employ  (1)  the  three  salts  KH2P04, 
Ca(X03)2,  and  MgS04,  (2)  the  four  salts  KH2P04, 
Ca(X03)2,  MgS04,  and  KX03,  or  (3)  the  four-salts  KH2P04, 
Ca('N03)2,  MgS04,  and  KC1,  if  we  use  the  best  proportion* 
of  the  salts  in  each  case  we  may  expect  to  obtain  about  the 
same  growth.  This  generalization  has  an  important  bearing 
on  the  whole  problem  of  physiological  balance  in  nutrient 
solutions  and  furnishes  what  may  be  important  suggestions 
bearing  on  our  general  conceptions  of  conditional  control  and 
conditional  optima  for  plant  activities. 


THE    RELATION    OF    THE    CONCENTRATION    OF    THE 

NUTRIENT  SOLUTION  TO  THE  GROWTH  OF  YOUNG 

WHEAT   PLANTS   IN   WATER-CULTURES 

By  S.  F.  TRELEASE 


In  these  experiments  the  salt  proportions  were  the  same  in 
all  the  different  solutions  of  each  series,  but  the  solutions 
differed  from  each  other  in  total  concentration.  Three  series 
of  cultures,  all  carried  out  at  the  same  time,  are  considered, 
each  series  including  a  concentration  range  of  from  0.5  to  7.0 
atmospheres.  A  different  set  of  salt  proportions  was  used  in 
each  series.  Six  plants  were  grown  in  each  culture  and  the 
cultures  were  in  duplicate,  upon  a  rotating  table.  The  ex- 
periment lasted  for  32  days,  from  January  23  to  February 
24,  1917,  the  solutions  being  renewed  every  4  days. 

In  the  first  series  the  nutrient  solutions  contained  the  4 
salts  KH2P04,  MgS04,  KC1,  and  Ca(X03)2  in  the  follow- 
ing relative  molecular  proportions:  1.000,  0.587,  0.485,  0.341. 
The  average  dry  weight  of  tops  and  the  average  total  water 
loss  by  transpiration,  for  six  plants,  are  shown  in  the  follow- 
ing table,  whch  also  shows  the  total  concentration  employed 
in  all  three  series. 


Concentration  of  Nutrient  Solutions          [424 

Concentration.,  Dry  Weight,  Tops.                  Transpiration. 

atm.  grants^  GO. 

0.5  0.926  651 

1.0  0.947  618 
1.6  '                                    1.152  646 
2.5  1.117  554 
3.5  1.030  468 
4.5  0.904  386 
5.5  0.821  311 

7.01  0.769  246 

For  this  particular  set  of  salt  proportions  the  maximum 
yield  of  tops  was  obtained  when  the  nutrient  solution  had  a 
total  osmotic  concentration  of  1.6  atm.  With  lower  con- 
centrations growth  was  considerably  less,  as  is  also  true,  and 
to  a  greater  degree,  with  concentrations  above  the  optimum. 
Between  the  concentrations  1.6  and  7.0  atm.  the  dry  weight 
of  tops  is  approximately  a  linear  function  of  the  concentra- 
tion, the  dry  weight  decreasing  as  the  concentration  increases. 
The  transpiration  values  show  the  same  general  relation  to- 
the  concentration,  except  that  below  1.6  atm.  the  decrease  is 
less  clearly  shown;  in  fact,  with  a  concentration  of  0.5  atm.. 
the  transpiration  is  slightly  higher  than  with  1.6  atm. 

In  the  second  series  the  culture  solutions  were  the  same 
as  those  just  described,  except  that  KC1  was  not  included, 
In  these  cultures  the  relations  of  dry  weight  and  transpira- 
tion, to  total  concentration,  were  essentially  the  same  as  in 
the  cultures  of  the  first  series,  with  KC1. 

In  the  third  series  the  salts  used  were  the  same  as  in  the 
first,  but  in  different  relative  molecular  proportions,  as  fol- 
lows :  1.000,  1.155,  7.282,  0.699.  The  relation  between  trans- 
piration and  concentration  was  the  same  as  in  the  first  series, 
but  in  this  case  there  was  a  perfectly  definite  maximum  of 
transpiration  at  1.6  atm.  For  production  of  dry  weight  of 
tops,  however,  while  the  general  relation  to  concentration  was 
the  same  as  in  the  first  two  series,  the  optimum  concentra- 
tion was  4.5  instead  of  1.6  atm. 

The  interesting  features  of  these  results  may  be  summar- 
ized as  follows:  (1)  Transpiration  and  dry  weight  showed 
an  approximately  linear  relation  to  the  concentration  of  the 
medium  above  the  optimum,  these  decreasing  with  an  increase 
in  concentration.  (2)  The  optimum  concentration  for  dry 


425]  8.  F.  Trelease  and  E.  E.  Free 

weight  of  tops  was  altered  from  1.6  atm.  to  4.5  atm.  by  chang- 
ing the  proportions  of  the  four  salts  used  in  the  first  and  third 
series.  (3)  With  the  salt  proportions  of  the  three  other 
salts  used  in  the  first  series,  the  omission  of  KC1  did  not  alter 
the  relation  between  growth  and  concentration. 


THE  EFFECT  OF  RENEWAL  OF  CULTURE  SOLUTIONS 

ON  THE  GROWTH  OF  YOUNG  WHEAT  PLANTS 

IN  WATER-CULTURES 

By  S.  P.  TKELEASE  and  E.  E.  FREE 


One  of  the  practical  problems. in  work  with  water-cultures 
is  that  of  the  frequency  with  which  the  culture  solution  must 
be  renewed  in  order  to  obtain  the  best  results.  This  note  re- 
ports experiments  in  this  connection  on  the  growth  of  young 
wheat  plants  in  the  nutrient  solution  found  by  Shive  x  to  be 
best  for  the  production  of  dry  weight  of  tops  In  wheat.  'Mie 
culture  jars  had  a  capacity  of  250  cc.  Six  plants  were  grown 
in  each  jar  and  each  culture  was  in  triplicate.  The  volume 
of  the  culture  solution  was  made  up  to  normal  by  the  addition 
of  distilled  water  every  4  days  or  oftener.  The  details  of  the 
technique  were  the  same  as  employed  by  SLive  -  Ail  cultures 
ran  41  days,  from  January  6,  to  February  16,  1916.  The 
results  are  given  in  the  following  table,  in  the  form  of  dry 
weights  of  tops  produced,  each  weight  being  the  average  of 
the  three  parallel  cultures, 

Dry  Weight, 
grams. 

Changed  daily .  . . , ,  .....  „  .....  „  .„„..»....    1.243 

Changed  every  3  days   1.012 

Changed  every  week 1.020 

Changed  after  1  week,  then  every  3  days  . , 0.995 

Changed  every  2  weeks ..»».».*. ,.;.  0.780 

Changed  after  2  weeks,  then  every  3  days 1.131 

Changed  after  2  weeks,  then  every  week v  ......   0.969 

Changed  after  1  month  0.654 

Not  changed  at  all 0.621 


1  Shive,  J.  W.,  "A  study  of  the  physiological  balance  in  nutrient 
media."     PhysioL  Res.   1 :  327-397.     1915. 


228  Renewal  of  Culture  Solutions  [42 S 

It  is  apparent  that  the  yield  is  better  the  more  frequently 
the  solution  is  changed.  If,  after  an  initial  period,  the  fre- 
quency of  changing  is  increased  the  yield  is  improved.  It  is 
important,  practically,  that  there  is  small  difference  between 
the  cultures  changed  every  3  days  and  those  changed  every 
week.  Daily  change  produces  substantial  improvement.  Al- 
lowing the  solution  to  remain  unchanged  for  so  long  as  2 
weeks  is  markedly  injurious. 

The  above  cultures  were  grown  on  a  rotating  table.  An 
additional  set  was  grown  in  the  same  greenhouse  at  the  same 
time  but  not  on  the  rotating  table.  The  results  follow: 

Dry  Weight. 

grams. 
Continuous   flow  of  solution   through   culture   jar    at 

rate  of  about  1  liter  daily   1.678 

Changed  every  3  days   1.222 

Not  changed  at  all    0.666 

This  experiment  is  not  strictly  comparable  with  the  one  done 
•>n  the  rotating  table,  but  it  seems  probable  that  continuous 
flow  of  the  solution  must  be  regarded  as  more  beneficial  even 
than  daily  change. 

Parallel  with  the  experiments  on  the  rotating  table,  one 
set  of  three  cultures  was  treated  by  removing  the  solution 
weekly  Lnd  shaking  it  with  bone  black.  The  solution  was 
then  filtered  and  restored  to  the  culture  jars.  These  cul- 
tures gave  an  average  yield  of  0.780  gram,  as  compared  with 
0.621  gram  for  the  unchanged  culture  not  treated  with  bone, 
black.  Evidently  the  bone  black  treatment  improved  the 
solution  slightly  but  did  not  correct  in  important  degree  the 
harmful  effects  of  infrequent  changing.  It  was  noticed  inci- 
dentally that  the  magnesium  injury  that  is  characteristic  of 
this  solution,  for  wheat,  appeared  more  frequently  and  se- 
verely when  the  changing  was  frequent  than  when  it  was 
not.  The  color  of  the  plants  was  greener  in  the  more  fre- 
quently changed  solutions. 


14  DAY  USE 

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